Ahead of the Dec. 12 poll, Scotland faces the prospect of leaving the EU against its will, Scottish National Party leader Nicola Sturgeon said Friday while calling on the British government to allow for a second independence vote.

"A vote for the SNP is a vote to escape Brexit," Sturgeon, who also heads Scotland's devolved government, said at the launch of its general election campaign.

Britons head to the polls on Dec. 12 for a snap election which Prime Minister Boris Johnson called to end the Brexit impasse, with polls showing the governing Conservatives ahead of Labour but by varying margins.

Scottish Nationalists will seek to form "a progressive alliance" with the opposition Labour Party if an election next month results in no one winning an overall majority, in return of holding a second independence vote in return, Sturgeon said. Opposition Labour leader Jeremy Corbyn has suggested he would allow another referendum if he wins the election.

In Scotland, the Scottish National Party (SNP) already has 35 out of 59 lawmakers, with some pollsters suggesting they will make further gains, positioning them as possible kingmakers. "If there's a hung Parliament ... SNP MPs will seek to form a progressive alliance to lock the Tories out of government," Sturgeon said at the start of the SNP campaign in Edinburgh.

"The SNP is not going to be giving support to parties that do not recognize the central principle of the right of the people of Scotland to choose their own future," she added.

Scottish voters opposed independence in a 2014 plebiscite but then backed remaining in the European Union in 2016, which the SNP has used to try and boost support for secession. In the 2016 Brexit referendum, 62% of Scottish voters opted to remain in the EU, while across Britain 52% voted for Brexit. Britain's delayed departure from the EU is now scheduled for Jan. 31 but could change depending on the outcome of the election, which was called by Johnson to try to end a Brexit impasse in Parliament.