London CNN —  

The stage has been set for a December general election in the UK after the opposition Labour Party swung behind the move, potentially paving a course out of the country’s paralyzing political impasse.

Labour leader Jeremy Corbyn confirmed his party would support Prime Minister Boris Johnson’s attempt in Parliament on Tuesday to force an early poll, all but ensuring it will take place.

Corbyn had opposed Johnson’s earlier attempts to force a vote, but said in a statement on Tuesday that his party will back it now that the European Union has extended the Brexit process until January 31.

“We will now launch the most ambitious and radical campaign for real change our country has ever seen,” Corbyn said.

The exact date is still unclear; Johnson will table a bill calling for a December 12 polling day, but could see it amended by opposition parties which are leaning towards a vote earlier in the same week. A senior government adviser told CNN on Tuesday that the government would accept an amendment for a December 11 vote, should it be tabled.

But the major theme of the election is obvious: campaigns will be dominated by Brexit, with the Prime Minister asking for a majority in Parliament that could support his plan to take the UK out of the EU.

He’ll face opposition from the Labour Party, which is calling for a confirmatory second referendum, and the resurgent Liberal Democrats, which want to revoke Article 50 and cancel Brexit altogether. And after failing to deliver his “do or die” promise to take Britain out of the EU by October 31, Johnson could also be squeezed from the other side by Nigel Farage’s hardline Brexit Party.

Labour had been the major holdout in the push towards an election, after the Liberal Democrats and the SNP dropped their opposition to a poll over the weekend.

“I have consistently said that we are ready for an election and our support is subject to a No Deal Brexit being off the table,” Corbyn said on Tuesday. “We have now heard from the EU that the extension of Article 50 to 31st January has been confirmed, so for the next three months, our condition of taking No Deal off the table has now been met.”

Johnson is enjoying a comfortable lead in opinion polls, but the same was true of Theresa May in 2017 when the former Prime Minister called her own snap vote.

In that election, a strong campaign resulted in Corbyn stunning pundits by picking up enough seats to deny May a majority in Parliament – setting the scene for two years of political chaos which Johnson inherited when he became Prime Minister during the summer.

The vote will be Britain’s first December election since 1923, when the first ever Labour government was elected.