UPDATE: 5:45 p.m. EST -- The British Parliament voted Wednesday for its military to join an international, U.S.-led coalition launching airstrikes in Syria and targeting the Islamic State group, the Associated Press reported. Prime Minister David Cameron argued the case for the Royal Air Force to participate in the bombing campaign, resulting in a 397-223 vote in the House of Commons. Labour Party leader Jeremy Corbyn, who opposed any military action from Britain, had previously called the notion of his country's participation a "reckless and half-baked intervention."

Original story:

As the debate over military action in Syria opened in British parliament Wednesday, Prime Minister David Cameron refused to apologize for his Tuesday comments calling those who opposed the motion to conduct airstrikes in Syria "a bunch of terrorist sympathizers," as the BBC reported. The U.K. Parliament is set to decide on whether to join French and U.S. allies in Syria in targeting the militant group known as the Islamic State group, ISIS or Daesh.

Cameron in a private meeting late Tuesday evening called on members of parliament from his Conservative Party to vote for the airstrikes. Labor Party head Jeremy Corbyn has been leading the opposition to airstrikes.

Cameron, without apologizing for his "terrorist sympathizer" comments that outraged many ranking politicians, urged members of parliament to vote for the measure on the floor for debate Wednesday. "The question before the House today is how we keep the British people safe from the threat posed by Isil and, Mr. Speaker, let me be clear from the outset this is not about whether we fight terrorism, it’s about how best we do that," Cameron said when he opened the debate Wednesday.

david cameron British Prime Minister David Cameron departed Number 10 Downing Street Wednesday in London, England. Photo: Getty Images

The U.S. has been leading a coalition targeting ISIS through airstrikes since 2014, having been joined by France, Turkey and several other international allies. ISIS seeks to depose Syrian President Bashar Assad while imposing Islamic law known as Sharia across a vast swath of Iraq and Syria. Following a spate of ISIS-organized terror attacks Nov. 13 in Paris, the U.S.-led coalition has upped its number of airstrikes, and has been looking for more support from its European allies.

Public support for the airstrikes has dropped by more than 10 percentage points in the past week, a recent survey from YouGov reported Wednesday. Around 59 percent of British citizens who responded to the poll last week said they supported airstrikes in Syria, with that number at 48 percent this week.

"In 7 days 5 million Brits change their minds on Syrian airstrikes. Concerned citizens or terrorist sympathisers?" wrote Jeremy Corbyn in a tweet posted to his verified account Wednesday.