LONDON (AP) — The leader of the Scottish government said Sunday that she will push on with her campaign to take Scotland out of the United Kingdom, even if she loses a Supreme Court case seeking authorization to call a new independence referendum.

First Minister Nicola Sturgeon wants to hold a referendum in October 2023, but the Conservative U.K. government in London has said no. Britain’s top court is due to hear arguments starting Tuesday on whether Scotland’s semi-autonomous administration can organize an independence vote without the London government’s consent.

Sturgeon, who leads the Scottish National Party, said that if her Edinburgh-based government loses the court case, she will make the next U.K. national election a de facto plebiscite on ending Scotland’s three-century-old union with England.

She did not give details of how that would work. A vote held without the approval of the U.K. government would not be legally binding.

Sturgeon said that if the courts blocked a referendum, “we put our case to people in an election or we give up on Scottish democracy.”

“It should be a last resort,” she said. “I don’t want to be in that position. I want to have a lawful referendum.”

Scotland and England have been politically united since 1707. Scotland has had its own parliament and government since 1999 and makes its own policies on public health, education and other matters. The U.K.-wide government in London controls matters such as defense and fiscal policy.

Scottish voters rejected independence by a margin of 55% to 45% in a 2014 referendum that was billed as a once-in-a-generation choice. Sturgeon’s government argues that Britain’s departure from the European Union and the coronavirus pandemic have upended politics and the economy and that it’s time to revisit the case for independence.

British voters narrowly approved Brexit in a 2016 referendum, but those in Scotland voted strongly to stay in the EU.

Sturgeon’s party leads a pro-independence majority in the Scottish parliament, together with the Scottish Green Party, and she maintains that support has created an “indisputable democratic mandate” for a new independence vote.

Sturgeon promised to produce documents in the coming weeks outlining the economic basis for independence and answering questions such as what currency the country would use after a split.

She said her goal of holding a referendum in a year’s time was realistic.

“There’s little point speculating on the outcome of a court hearing, but should that be yes, we have the plans ready to go to legislate,” she said.

Polls suggest Scotland is about evenly split on independence. Labour Party politician Alistair Darling, a former U.K. Treasury chief, said polls also show a majority of Scots do not want a referendum anytime soon.

“This country is tearing itself apart. And that uncertainty is damaging to our growth prospects and to our wellbeing,” Darling said.