Supporters of Jeremy Corbyn, a candidate in the Labour Party leadership election, listen to speeches at Rock Tower in London Sept. 10, 2015. Getty Images

UPDATE: 1:35 p.m. EDT — The man who on Thursday stabbed and shot a British Labour Party member of Parliament to death has been identified as Tommy Mair, British news outlet the Sun reported. The 52-year-old man reportedly shot Jo Cox three times before stabbing her multiple times. Mair's homicidal attack was apparently inspired by his opposition to the United Kingdom staying in the European Union. Cox championed the opposite position against a so-called Brexit.

Her husband reportedly told the Independent that he didn't want her death to be in vain.

Cox was rushed to a hospital immediately following the attack and into surgery, but she ultimately succumbed to her injuries. She is the first British elected official to be murdered in more than a quarter of a century.

Mair was arrested and was in police custody.

UPDATE: 12:38 p.m. EDT — Jo Cox's fellow politicians reacted Thursday with shock and disbelief to the news that the Labour Party member of British Parliament died from a "horrific murder" after being shot and stabbed by an attacker earlier in the day.

Cox, 41, was meeting with a group of her constituents when an as-yet unidentified man launched his attack against her. The man, 52, was ultimately arrested and police have said there is no other suspect, the BBC reported.

As a result of Cox's tragic death, campaigning for the United Kingdom referendum to leave the European Union — or, the so-called Brexit — was suspended Thursday, something that a handful of local politicians and groups complied with and applauded.

UPDATE: 12:18 p.m. EDT — British Labour Party member of Parliament Jo Cox has reportedly died from the injuries she sustained Thursday after an attacker shot and stabbed her during a meeting with constituents in England.

UPDATE: 10:37 a.m. EDT — While British member of Parliament Jo Cox remained in critical condition Thursday after a stabbing and shooting reportedly linked to the so-called Brexit vote over the country’s future inside or outside the European Union, some social media users recalled another U.K. lawmaker who was targeted for his views: Stephen Timms. In 2010, a 21-year-old student attempted to murder Timms, another Labour member of Parliament, for voting in favor of the Iraq War, according to BBC News. He survived.

Like Timms, Cox was wounded Thursday while at a so-called advice surgery. Advice surgeries are periodic events where politicians can speak with constituents needing assistance. She was attacked by a man who reportedly yelled, “Britain First!” — which could indicate he opposed her view that the U.K. should remain in the EU.

“This is a shocking incident. We do not know the reasons for this attack, but my friend and close colleague is said to be critically ill,” Shadow Attorney General Karl Turner told the Telegraph. “Obviously my thoughts are with her and her husband and family at this time.”

NBC News reported Thursday that 53 percent of British voters said they wanted to leave the EU in a new poll. The Brexit vote is set for June 23.

Looking for more context? Read International Business Times’ in-depth reporting on the Brexit referendum:

UPDATE: 10:23 a.m. EDT — The British lawmakers supporting the initiative to leave the EU in the Brexit vote next week have stopped bus campaigning for the day after a politician on the other side of the debate, Jo Cox, was shot and stabbed in Birstall, England, the Telegraph reported.

Cox, a Labour Party member of Parliament, has been pushing voters to cast their ballots to remain in the EU. She was shot and stabbed Thursday by a man who reportedly was heard yelling, “Britian First.”

“There was a guy who was being very brave and another guy with a white baseball cap who he was trying to control, and the man in the baseball cap suddenly pulled a gun from his bag,” eyewitness Hithem Ben Abdallah told the Press Association. “He was fighting with her and wrestling with her and then the gun went off twice and then she fell between two cars and I came and saw her bleeding on the floor.”

The man was arrested, and Cox was in critical condition. Her name was trending on Twitter shortly thereafter.

UPDATE: 9:41 a.m. EDT — Jo Cox, a member of Parliament in the U.K., was in “critical condition” Thursday after being shot and stabbed in Birstall, England, police told BBC News. A 52-year-old man was arrested in connection with the incident.

“A man in his late 40s to early 50s nearby also suffered slight injuries,” West Yorkshire police said in a statement cited by the Telegraph. “There are no further details at present. Police presence in the area has been increased as a reassurance to the community.”

Cox, a Labour Party politician, has recently pushed for Britain to remain in the EU in the Brexit referendum next week. Witnesses to the incident Thursday reportedly heard the suspect yell, “Britain First!” — a possible indication he wants the country to leave the union.

Original story:

Jo Cox, a member of Parliament in the U.K., was shot and stabbed in Birstall, England, Thursday afternoon, according to media reports. Cox was at her advice surgery, a regular constituent outreach event, when she was attacked, ITV reported. Cox’s assistant confirmed the incident to the Telegraph.

Cox, 41, won the seat for the Batley and Spen constituency in the 2015 general elections. A Labour Party politician, she’s recently been promoting the “remain” campaign ahead of the so-called Brexit vote on whether Britain should leave or remain in the European Union. The vote is set for June 23.

Condolences began to pour in on social media after the shooting and stabbing.