A Vote Leave campaign poster rests next to a Vote Leave bus during a nationwide bus tour for the "leave" campaign linked to Britain's referendum on its future in the European Union, May 11, 2016. Luke MacGregor/Bloomberg via Getty Images

UPDATE: 9:01 a.m. EDT — We've started a new live blog for Friday's news, including reaction from the White House and Pope Francis on the Brexit referendum. Follow updates here.

UPDATE: 1:03 a.m. EDT — The United Kingdom has chosen to leave the European Union, the BBC reports. The "leave" campaign has officially passed the winning line, securing 16.8 million votes against 15.7 million for "remain."

UPDATE: 12:40 a.m. EDT — Eighty-four Conservative lawmakers in the U.K. have written to David Cameron, urging him to stay on as the country’s prime minister. Cameron, who has been the prime minister since 2010, headed the "remain" campaign, but many of his MPs supported the other side.

“We believe whatever the British people decide you have both a mandate and a duty to continue leading the nation implementing our policies,” the MPs reportedly wrote in the letter.

Cameron, whose fate now hangs in the balance, is expected to address the nation later Friday. Currently, with over 93 percent of the votes counted, the "leave" campaign has won 51.8 percent, while the "remain" camp has garnered 48.2 percent of the vote.

UPDATE: 11:49 p.m. EDT — With over 83 percent of the votes now counted, the BBC has forecast that the U.K. has chosen to leave the European Union. The pro-Brexit camp currently has 51.7 percent of the vote, while the “remain” camp has secured 48.3 percent.

Global investors, meanwhile, are clearly spooked. The pound sterling fell to a 31-year-low of $1.35, while markets in Asia, including Japan’s Nikkei 225, India’s S&P BSE Sensex and China’s Shanghai Composite index, plummeted. Gold prices, on the other hand, surged over 7 percent as investors flocked to hoard up the safe-haven asset.

“The overconfidence in the U.K. to vote to remain in the EU has seriously come back to bite traders in the early hours of the morning,” Trevor Charsley, a currency trader at AFEX, told the Wall Street Journal. “While there is still a long way to go, it is clear that people has significantly underestimated how many would vote to leave on Thursday."

UPDATE: 10:56 p.m. EDT -- Results from Thursday's Brexit referendum are arriving from throughout the U.K., sometimes falling short of predictions. Oxford, for example, was predicted to back "remain" by 75.5 percent, but the actual result was slightly over 70 percent, Reuters reported.

Signs that the "leave" camp may win were cheered by U.K. Independent Party leader Nigel Farage in a complete turnaround from earlier pessimistic statements that had some claiming he had conceded defeat:

In other urban areas, Liverpool voted to remain in the European Union, 58 percent to 42 percent, while "remain" won in Glasgow, Scotland, 62 percent to 33 percent, the BBC reported.

"Remain" backers were looking to London voters to keep the country in the EU. Early reports said turnout in the capital was lower than expected.

Nearing 11 p.m. EDT, results compiled by the BBC were showing the following counts:

England: 6.2 million votes for "leave" to 5.2 million for "remain"

Northern Ireland: 310,825 for "leave" to 380,544 for "remain."

Scotland: 897,801 for "leave" to 1.5 million for "remain."

Wales: 732,310 for "leave" to 615,679 for "remain."

UPDATE: 10:05 p.m. EDT – At European Union headquarters in Brussels, the lights are on all night as EU officials watch the results.

The British pound saw one of its sharpest drops ever overnight in London, shedding a dime against the U.S. dollar between the time EU referendum vote polls closed in the U.K. at 10 p.m. and 1:09 a.m. Friday morning local time, from $1.501 to $1.405. The sterling recovered from this nearly 6 percent drop to about $1.45. Fears that Britain would pull out of the EU led currency exchange outlets to stock up on euros and dollars in anticipation of stronger retail demand.

Sure enough, Britons were lining up before the vote to hedge their Brexit bets. The pound was still down about 3 percent overnight as the “leave” camp was making unexpected gains. Here’s a chart of the how the pound fared against the U.S. dollar in the early hours of the referendum poll counting.

UPDATE: 9:25 p.m. EDT – London stock exchange futures are diving as investors bet on a lower open on Friday following Thursday's referendum on Britain's EU membership. The FTSE 100 Futures dropped nearly 6 percent shortly after 9 p.m. EDT as investors wager that the “leave” camp will prevail, creating tumult in global markets early Friday.

U.S. stock futures were also tipping into the red, with Dow futures plunging 130 points, suggesting a lower open Friday in U.S. markets. Asian stocks opened lower on the last trading session of the week. Tokyo’s Nikkei 225 was down 1.6 percent while Hong Kong’s Hang Seng shed 1.8 percent.

The British pound dropped to $1.40 against the U.S. dollar, losing a dime since Brexit polls closed at 10 p.m. London time. The Japnese yen, a safe-haven currency, recovered form earlier losses, which put downward pressure on Japanese stocks.

UPDATE: 9:17 p.m. EDT — The big wagering house Ladbrokes is now tilting toward a Brexit result:

UPDATE: 8:30 p.m. EDT — Turnout in London, a "remain" stronghold, appears to be 2 percent or 3 percent lower than expected. Meanwhile, a live blog run by the University of East Anglia is now forecasting a narrow win for "leave."

UPDATE: 7:50 p.m. EDT — The British pound dropped to $1.44 against the U.S. dollar Thursday after very early results showed wider-than-expected support for a British exit from the European Union.

The pound had touched $1.50, its highest level this year, but its value dropped by 6 cents just minutes after election results from Newcastle, the first election district to report, showed support for Britain to "remain" in the EU, 50.7 percent to 49.3 percent, the Telegraph reported.

Meanwhile, voters in nearby Sunderland backed the "leave" campaign by a wide margin, 82,394 votes to 51,930.

In the days leading up to Thursday's Brexit vote, U.S. fund investors pulled out of riskier funds, withdrawing a total of more than $6 billion, Reuters reported, citing information from Lipper.

UPDATE: 7:10 p.m. EDT — The traditional race to be the first district to report results of a vote has begun in Britain, ABC News reported. Officials and volunteers were scrambling Thursday to count the results of the nation’s historic referendum regarding its future in the European Union.

Sunderland, a city in Northeast England, was expected to give its results at 12:30 a.m. local time (7:30 p.m. EDT). But nearby Newcastle was also vying to be first.

In financial markets, the British pound hit its highest level against the U.S. dollar this year after polls closed, as currency traders bet that Britain would remain in the EU. The pound briefly topped $1.50. Traders likely saw an online survey showing a four-point lead for the “remain” effort.

U.S. Dow index futures – in which investors make overnight bets on how the U.S. market will open the following day – briefly gained 100 points and continued to indicate a higher open in New York City on Friday.

UPDATE: 5:25 p.m. EDT — Polls have officially closed in Britain, but the Electoral Commission says everyone who makes it into the queue by 10 p.m. (5 p.m. EDT) will be allowed to cast their ballot on whether Britain should remain in the European Union, the Telegraph reported.

Which way voters were leaning in the Brexit decision wasn't certain. But U.K. Independence Party leader Nigel Farage seemed to call the results when he told Sky News that it “looks like ‘Remain’ will edge it," referring to supporters of the country’s continued EU membership.

Results of the referendum were scheduled to be announced at 7 a.m. Friday, local time (2 a.m. EDT) in Manchester Town Hall. An average of six polls for the historic referendum were well within any margin of error, with 51 percent in favor of "remain" in the EU and 49 percent supporting "leave."

UPDATE: 4:18 p.m. EDT — With less than an hour to go before polls close, both sides of the “Brexit” referendum on Britain's future in the European Union are still making their pitches to the public.
“Don’t lose this chance to make today our Independence Day!!!” wrote former London Mayor Boris Johnson in an email to his subscribers, the Guardian reported.

The Labour Party, which supports Britain remaining in the EU, urged its constituents to get out and vote: “If you haven’t voted yet — don’t miss out on being a part of it, There’s still plenty of time, polls are open until 10 p.m.” [5 p.m. EDT]

Two activists with the European Union flag and Britain's Union Jack painted on their faces kiss to protest a British exit from the European Union, in Berlin, June 19, 2016. Hannibal Hanschke/Reuters

UPDATE: 2:15 p.m. EDT — Thousands of potential voters in the U.K. were stranded Thursday as transportation problems hit major hubs across London. Waterloo station, which serves millions of passengers every year, was having service issues, the Guardian reported. Commuters shared posts on social media about hoping to reach the polls to vote in the historic referendum on whether the U.K. will remain in the European Union.

UPDATE: 1:22 p.m. EDT — The U.K.'s independent Electoral Commission reminded voters Thursday to not take any pictures inside the polling station, including selfies. The group’s website reads: "Pictures taken outside the polling station are great to use on social media and encourage your friends and family to vote, but don’t take any photos inside the polling station as you might find yourself in breach of secrecy of the ballot requirements."

UPDATE: 1:06 p.m. EDT — A senior official from the euro-skeptical, anti-immigration Alternative for Germany party wants Germany to hold its own Brexit to end European Union membership, the Wall Street Journal reported Thursday.

"People here in Germany should also be allowed to vote on whether to stay in the EU," Beatrix von Storch, a member of the European Parliament, told German broadcaster Phoenix. "For Germany's behalf, we want far-reaching reforms of European treaties and less power for the European level."

Far-right leaders in France, Greece and other nations have also flirted with the idea of holding a referendum on European Union membership.

UPDATE: 12:52 p.m. EDT — British Prime Minister David Cameron hit Twitter Thursday to rally support for the European Union as polls showed a close race between the "leave" and "remain" camps battling for votes. But the problem, the New York Times noted, was "of his own making."

Cameron promised to hold a referendum on European Union membership if he was re-elected in 2015. He was, so earlier this year he called for the so-called Brexit vote.

"But what seemed then like a relatively low-risk ploy to deal with a short-term political problem has metastasized into an issue that could badly damage Britain’s economy, influence the country’s direction for generations — and determine Mr. Cameron’s political fate," the New York Times noted.

Cameron's tweet Thursday signaled how eager he was for the vote to somehow work out in his favor:

UPDATE: 12:34 p.m. EDT — Denmark’s prime minister said European leaders would meet Friday to discuss what steps to take if the U.K. votes Thursday to exit the European Union. Lars Loekke Rasmussen said “it would be a tough job” but he had high hopes for “a peaceful divorce.” The Brits and the Danes joined the EU at the same time in 1973.

Meanwhile, Norwegian Foreign Minister Boerge Brende, wrote Thursday on Twitter “Fingers crossed for (hashtag) remain.” Norway has twice voted against joining the EU.

UPDATE: 12:26 p.m. EDT — Some Brits are convinced the government is trying to steal the British referendum after voters were provided with pencils to fill in their ballots instead of pens, which can smear. Proponents of the campaign to leave the European Union told voters Thursday to bring pens to the polls to make sure their ballots later won't be erased, the Independent reported.

UPDATE: 12:10 p.m. EDT — A library where a British lawmaker was killed last week amid a heated debate over whether the U.K. should leave the European Union was serving Thursday as a polling station for the so-called Brexit vote. Some police officers guarded the library a week after Jo Cox was stabbed and shot by a man who yelled "Put Britain first" before the killing.

David Smith, the deputy returning officer in the area, told the Guardian turnout seemed high, or about more than 80 percent. A moment of silence was held to honor the member of Britain's Parliament during the morning voting hours.

Smith said he previously saw high turnout in the election where Cox was elected. "I work with politicians everyday and they have a bad press, but everything they say about her is true," he said.

Cox, a 41-year-old mother of two, supported the "remain" fight to keep the U.K. in the EU.

Helen Joanne "Jo" Cox MP | InsideGov

UPDATE: 11:40 a.m. EDT — Proponents of the so-called "leave" campaign urging Brits to vote to exit the European Union Thursday sent out a last-minute email to supporters warning about high turnout rates in London and Scotland, areas that are believed to support the "remain" vote. The Mirror, which opposes the Brexit, reported that the email read: "don’t let them get away with it!"

It goes on: "There is a very real chance that voters in London and Scotland will vote to keep us in the EU today despite the heartlands of the country voting to leave. We need YOUR help to stop this from happening. Please call, text or email your friends and family who have not voted and make sure they Vote Leave today. If you don’t want people in London to force you and your family to stay in the EU please email and call all your friends and make sure they Vote Leave today!"

UPDATE: 11:26 a.m. EDT — Coldplay singer Chris Martin said the Glastonbury Festival scheduled this week in England is a time to bring the U.K. together amid a contentious vote Thursday on whether to leave the European Union.

"We’re in a time when a lot of things separate and divide us – Brexit, walls – so hopefully our concerts are saying the opposite at the moment," Martin told the Guardian ahead of his performance scheduled for Sunday. "Everyone in our band comes from disparate places, but Glastonbury is the one place we all feel we come from.”

Martin clarified that he wasn't making a political statement. “I’m really talking about how we’re playing to a lot of hungover people who are a bit muddy. Where we’re at in our minds at the moment, it feels a little freer, and I think we’re really excited about singing together. I don’t think it’s the time to be debuting our noodly B-sides.”

UPDATE: 11:05 a.m. EDT — Business leaders, politicians, celebrities and others have weighed in on the Brexit debate. One big missing voice? The Queen. Here's International Business Times' inactive graphic on how famous Brits are voting Thursday in a historic vote to leave the European Union.

UPDATE: 10:42 a.m. EDT — Many Brits were nervous Thursday about how a referendum on the U.K. leaving the European Union would go down. Polls show the "leave" and "remain" camp evenly matched.

“I’m going to bed tonight with a sleeping pill because I’m terrified of what’s going to happen tomorrow,” Rina Picciotto, a 67-year-old North London resident, told the Wall Street Journal after voting.

The New York Times put together a photo gallery here about the referendum.

UPDATE: 10:14 a.m. EDT — German tabloid Bild has penned a long list of bribes to persuade Brits to stay in the European Union, including: "We won’t make any more jokes about Prince Charles’ ears. We won’t wear sun cream on the beach in solidarity with your sunburn. We will willingly provide the villain in every Bond film. We’ll put through an E.U. directive which forbids foam on our beer."

UPDATE: 9:50 a.m. EDT — Nicola Sturgeon, the first minister of Scotland, voted for the U.K. to stay with the European Union Thursday at her local polling station in Glasgow. Sturgeon supports an independent Scotland.

"I did so with head and heart because being in [the] EU is best for Scotland," she tweeted.

UPDATE: 9:30 a.m. EDT — The odds of British voters opting to leave the European Union in a historic referendum Thursday dropped from about 23 percent to 15 percent in just a few hours, according to bookmakers' odd.

UPDATE: 9:16 a.m. EDT — The British referendum on leaving the European Union reads simply: "Should the United Kingdom remain in the European Union or leave the European Union?" That's the kind of plain language the U.S. needs to adopt, Vox argued Thursday.

"A study of more than 1,200 state-level ballot questions that voters across the US were asked to approve between 1997 and 2007 found that, on average, they were written at a 17th-grade level — in other words, you’d need more than a four-year college degree in order to understand what you were being asked to vote on," Vox writes. Read more here.

Voter Registration and Turnout Over Time | InsideGov

UPDATE: 8:46 a.m. EDT — The U.K. is going to the dogs. As Brits head to their local polling stations Thursday to vote on whether the U.K. should remain in the European Union, many voters are bringing their dogs and tweeting about it. #DogsAtPollingStations was trending Thursday on Twitter.

UPDATE: 8:46 a.m. EDT — France, Italy, Sweden and Greece are closely watching a U.K. referendum Thursday on whether to leave the European Union ahead of potential copy-cat votes in those nations. International Business Times has a helpful explainer on the history of the European Union and why so many nations are now considering leaving it here.

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Notices are displayed outside a polling station in central London, June 23, 2016. Voters will decide whether to remain in the European Union. Reuters

UPDATE: 8:25 a.m. EDT — Recent college graduates could have a hard time finding jobs in banking, finance, retail, media, technology and law if Brits vote Thursday to leave the European Union, according to a new study by PathMotion, an employer-to-candidate engagement platform. PathMotion CEO David Rivel said employers have confirmed that there will be a loss of jobs for recent graduates if the so-called Brexit gets passed.

More than 5,500 graduates are expected to land jobs in 2016, but that number could shrink if the U.K.'s economy downsizes after leaving the EU, the study determined.

“British graduates are not protected, despite some employers shifting from EU to British graduates. The survey also reveals employers are worried at the prospect of losing access to the talent pool that they can already tap into," Rivel said.

Member States of the European Union | Graphiq

UPDATE: 8:05 a.m. EDT — Belgian Prime Minister Charles Michel said the European Union must shift its focus amid growing political movements urging national leaders to leave the alliance. As the U.K. votes Thursday on whether to leave the EU, Michel said European leaders must meet regardless of how the vote goes to discuss why so many seem to want, “a new Europe, another Europe," he said.

“There are signals everywhere — not only in the U.K. We feel there is a growing doubt about the European project,” Michel said.

UPDATE: 7:56 a.m. EDT —Turkish President Recep Tayyip Erdoğan said Wednesday Turkey may holds its own Brexit-style referendum about its potential European Union membership because EU officials don't want a “Muslim-majority country."

“We can stand up and ask the people just like the British are doing,” he said according to a report by the state-run Anadolu news agency. “We would ask: ‘Do we continue the negotiations with the European Union or do we end it?’ If the people say ‘continue,’ then we would carry on.”

European officials have promised Turkey membership since at least 1963, but Ankara didn't formally apply for membership until 1987 and accession talks only began in 2005. Erdoğan has said Europe is stalling.

Trade Between Turkey with OECD Countries | FindTheData

UPDATE: 7:42 a.m. EDT — Many undecided voters will likely stay at home in the U.K.'s referendum Thursday to leave the European Union and low turnout could help those who want change, U.K. Independence Party leader Nigel Farage said.

"It's all about turnout and those soft 'remainers' staying at home," Farage, a "leave" supporter, told the Associated Press outside his home as he collected his morning newspapers. "I do think we are in with a very strong chance, I do genuinely."

Largest Trade Partners for United Kingdom | FindTheData

UPDATE: 7:20 a.m. EDT — The U.K.'s credit rating could take a hit if voters decide to leave the European Union Thursday in a historic referendum, Moritz Kraemer, Standard and Poor’s chief sovereign ratings officer, told German daily Bild. Britain's AAA credit rating would likely be downgraded shortly after the "leave" vote largely because there is no real plan for what would happen next, he said.

“If Great Britain decides for a Brexit in the EU referendum on Thursday, then the AAA credit rating would come due and would be downgraded within a short period of time,” he said.

UPDATE: 7:01 a.m. EDT — The British referendum to leave the European Union is spooking some U.S. business owners who depend on the London’s trade laws with mainland Europe to push their products. International Business Times talked with companies based in New York City, including the Brooklyn Brewery, a craft beer company, about why a Brexit could be bad news for the U.S. Read the story and watch a video about the U.S. ramifications of a Brexit here.

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For the Brooklyn Brewery, a craft beer company created by a former Middle East correspondent for the Associated Press and his banker neighbor, a Brexit could be a major setback. International Business Times

UPDATE: 6:30 a.m. EDT — British newspapers have gone to battle in the so-called Brexit, urging their readers to take a side in the vote that could reshape Europe. Among those that support the U.K. staying in the European Union is the Times, the Guardian, the Independent, the Economist and the Financial Times. The "leave" camp includes the Daily Mail, the Sun, the Sunday Times, the Telegraph and the Spectator.

"The heaviest contribution of Leave-supporting papers has been to focus relentlessly on immigration and free movement of labor in the EU, the topic that creates most angst among Leave voters. Papers that back remaining in the EU, including the Guardian and the Financial Times, have given more space to economics articles and comment about the financial risks of leaving," the Financial Times wrote.

UPDATE: 6:10 a.m. EDT — This isn't the U.K.'s first big vote on British independence. In 1975, just two years after the U.K. joined the European Economic Community, voters weighed in on staying with the alliance and opted to keep close ties with Europe. Scottish voters confronted an independence referendum in 2014, but decided to stay within the U.K. In all, this is the U.K.'s third nationwide referendum.

Trade Between United Kingdom and EU Countries | FindTheData

UPDATE: 5:53 a.m. EDT — The British referendum to leave the European Union has fueled massive bets on the future of the U.K., the New York Times reported Thursday. The Brexit vote saw wagers worth more than 3 million pounds, or $4.4 million, this week, with most of it coming from online transactions and supporting the "remain" vote.

"The betting is just massive," Mike Smithson, founder and editor of PoliticalBetting.com, told the New York Times, calling the referendum, "the biggest political betting event of all time, anywhere."

UPDATE: 5:40 a.m. EDT — Thorbjørn Jagland, the secretary general of the Council of Europe, said Europe will continue relations with the U.K. if Brits vote Thursday to exit the alliance.

“I was chairing the committee that awarded the Nobel peace prize to the European Union so the answer is evident [on where I stand] but I really hope that the UK would stay. I also believe that if we get the opposite result, Europe has to deal with it in a rational way, so Europe will survive,” he told the Guardian. “It is up to the people of United Kingdom to decide, it’s a democratic referendum, we have to respect that but I hope results would be clear."

He said the U.K. won’t be shunned if it chooses to distance itself from the EU. “British islands will continue to exist and British people will continue to exist as part of Europe, so whatever happens we cannot start isolating each other in Europe once again, it would be ridiculous,” he said.

UPDATE: 5:28 a.m. EDT — Polls show a close showdown in the U.K. Thursday as voters consider leaving the European Union. An Opinium survey gave the "leave" vote a one-point lead, 45 percent to 44 percent, while ComRes for the Daily Mail and ITV News had the "remain" vote at 48 percent over the "leave" vote with 42 percent support. A YouGov poll had the "leave" campaign up by two points, 51 percent to 49 percent. Results are expected starting Friday morning.

UK Net Budgetary Contribution to the EU | InsideGov

UPDATE: 5:15 a.m. EDT — It's a national vote with major implications for the global economy. But what do celebrities have to say about the British referendum to leave the U.K.?

Hundreds of actors and creative leaders have weighed in on the so-called Brexit in recent weeks. More than 280 stars signed a letter in May that declared: "Britain is not just stronger in Europe, it is more imaginative and more creative, and (the U.K.'s) global creative success would be severely weakened by walking away." Supporters included Patrick Stewart, Benedict Cumberbatch, Helena Bonham Carter, Jude Law, Keira Knightley and Eddie Izzard. On the pro-Brexit side, there are Michael Caine, Elizabeth Hurley and Joan Collins. NBC News has a full roundup of celeb votes here.

UPDATE: 5:05 a.m. EDT — British voters must have faith in the U.K. and vote to leave the European Union Thursday, former London Mayor Boris Johnson said in a last-minute campaign pitch. In an exclusive interview with the Telegraph, Johnson said the U.K. can “prosper mightily” outside the European Union despite warnings that a so-called leave vote would hurt trade.

“Our campaign is about self-belief,” he said. “It is about trusting the instincts of the British people, trusting in our democracy, trusting in the institutions that have evolved over a long time. Our campaign is about accountability."

Read the rest of the interview here.

Brexit Opinion Polling: Remain vs. Leave | Graphiq

UPDATE: 4:45 a.m. EDT — Oil prices saw a slight uptick Thursday as the market watched the voting in the U.K. on the so-called Brexit vote. Brent's front-month August contract was up 5 cents at $49.93 a barrel after closing Wednesday at 74 cents, or 1.5 percent, at $49.88 a barrel. U.S. oil was up 1 cent to $49.14 a barrel, Reuters reported.

UPDATE: 4:35 a.m. EDT — Investors in Asia waited nervously for the results Thursday of a U.K. vote on leaving the European Union. As markets closed, Australia's ASX 200 climbed 9.75 points, or 0.19 percent, at 5,280.70, while in Korea, the Kospi dropped 5.87 points, or 0.29 percent, at 1,986.71. Chinese mainland markets lost 13.49 points, or 0.46 percent, to 2,892.05. In Hong Kong, the Hang Seng index saw a 0.2 percent increase in late afternoon trading.

Original story:

The vision for a united Europe has taken a beating in recent years, with thousands of refugees demanding to be let in, a devastating recession that threatened to undo decades of economic progress in Spain, Portugal, Italy and Greece, and a growing political movement calling for isolation and closed borders. But a referendum before voters in the United Kingdom Thursday could result in the European Union losing a member for the first time, potentially inspiring other countries to also exit the alliance and setting off a series of economic consequences that could weaken some of the world's most powerful nations if the warnings are accurate.

So, yes, it's a big day for Europe. Polling stations in the U.K. opened at 7 a.m., local time, or around 2 a.m. EDT, with a historic 46.5 million people registered to vote in the so-called Brexit. Polls were scheduled to close at 10 p.m., local time, or 5 p.m. EDT.

The uncertainty surrounding the vote has hit global markets in recent weeks and weakened the pound sterling against the dollar and the euro. London began referendum day with heavy rain and localized floods that disrupted trains and shut down roads, NBC News reported.

The Palace of Culture and Science is illuminated in Union Jack colours by Warsaw's capital authorities in support of Britain staying in the EU, in Warsaw, Poland June 22, 2016. Reuters

Polls show a close battle between the "leave" campaign, which has urged voters to imagine a future outside the EU, and the "remain" camp, which argues that the U.K. could not thrive with the European Union's backing. Results were expected to come Friday morning.

Prime Minister David Cameron has urged voters to keep the status quo, while former London Mayor Boris Johnson has been an outspoken "leave" proponent. World leaders have also urged the U.K. to stay put, including U.S. President Barack Obama and German Chancellor Angela Merkel, who has said she hopes British voters will choose to remain “for the benefit of all of us."

The U.K. has seen explosive economic growth since joining the European Economic Community in 1973. Exiting the EU could mean years of creating new trade deals with the remaining 27 members of the EU and about 50 additional countries with which the EU has preferential deals. Obama, for example, has warned Britain would be “at the back of the queue” for a trade deal if the Brexit saw the U.K. leave the union.