LONDON • Seven Labour politicians quit the UK’s main Opposition party yesterday as Brexit cracked open the structures that have defined British politics for decades.

At a snap press conference in London, the MPs stood up one by one to explain why they have resigned in protest at Jeremy Corbyn’s leadership of the Labour Party.

They will now sit in an “Independent Group” and are aiming to become a new force in UK political debate.

The split has been rumoured for months, but with less than six weeks until the UK is due to leave the European Union (EU), many in the group said Corbyn’s failure to take a decisive stand against Prime Minister Theresa May’s Brexit policy proved to be the “tipping point”.

Others cited the Labour leader’s failure to stamp out antisemitism among his supporters. Veteran MP Mike Gapes, who had been a member of the party for 50 years, said he is “sickened that the Labour Party is now a racist antisemitic party”.

Chuka Umunna, Labour’s former chief business spokesman who was once mooted as a future party leader, said mainstream political parties have “become the problem” and urged politicians from across the political spectrum to join the new group.

There has been speculation that some Conservatives will also split away from May’s party.

“We invite you to leave your parties and help us forge a new consensus on a way forward for Britain,” Umunna said.

“You don’t join a political party to spend years and years fighting the people within it, you get involved in politics, you join a party, to change the world.”

Corbyn was ready for the announcement when it came.

“I am disappointed that these MPs have felt unable to continue to work together for the Labour policies that inspired millions at the last election and saw us increase our vote by the largest share since 1945,” the Labour leader said in a statement.

He accused the Tories of “bungling Brexit” and insisted he had set out “a unifying and credible” alternative plan.

“Now more than ever is the time to bring people together to build a better future for us all,” he said.

Luciana Berger, who employed a bodyguard to protect her from abusive Corbyn supporters when she attended the party’s annual conference in Liverpool last year, said the leadership’s failure to deal with antisemitism had left her with no option.

“The leadership has willfully and repeatedly failed to address racism against Jewish people within its ranks,” Berger said.

“I am leaving behind a culture of bullying, bigotry and intimidation and I look forward to a future serving with colleagues who respect each other and who are committed to working together for our great country.” — Bloomberg