The separatist leader of Scotland's devolved government plans to ask the public next year whether the nation should remain within the United Kingdom.

Nicola Sturgeon, who is first minister of the Scottish Parliament and leader of the Scottish National Party, or SNP, said on Tuesday she wants the vote, which will be the second referendum-type poll to be held on the issue in nine years, to be staged on Oct 19, 2023.

But the UK government has said it will not allow a second independence referendum yet, because such votes should be held no more than once in a generation.

Sturgeon said she plans to get around the central government's objections by staging a non-binding plebiscite, instead of a legally-binding referendum.

She also insisted the UK's exit from the European Union since the first referendum, a departure strongly opposed by a majority of Scots, means enough has changed recently to justify asking people once again how they feel about independence.

"It is time to give people the democratic choice they have voted for (in elections for the Scottish Parliament), and then, with independence, to build a more prosperous, fairer country in a true partnership of equals between Scotland and our friends in the rest of the UK," she said.

The 2014 referendum was won by those wanting Scotland to remain part of the UK, with 55 percent of votes favoring the union.

Sturgeon has put her case for a second vote several times recently, and has described the UK government's unwillingness to grant one as "continued efforts to thwart the will of the people".

She laid out her case in detail earlier this month in a written paper that explained how the UK is supposed to be a voluntary partnership between independent nations that can be withdrawn from at any time.

"The UK government is in no position to lecture any other country about the need to respect democratic norms if it is intent on trying to thwart democracy at home," she said. "The UK is either a partnership of consent or it is not a partnership worthy of the name."

The SNP is being supported in its push for a second independence vote by the Scottish Greens. Together, the two parties have a majority of lawmakers, or MSPs, in the Scottish Parliament.

"Last May, the people of Scotland said yes to an independence referendum by electing a clear majority of MSPs committed to that outcome," she said. "The democratic decision was clear."

But the UK government has countered by saying the SNP was the only Scottish party to campaign for breaking away from the rest of the UK, and that less than a third of Scottish voters backed the party in the last election.

The UK government's Scottish secretary, Alister Jack, said London will, therefore, refuse to allow a referendum.

Sturgeon, though, said she believes a lawful vote can be held without London's approval if it is not legally binding and is merely an indicative vote of people's opinions on the issue. And she has asked Scotland's top law officer, the lord advocate, to ask the Supreme Court whether the Scottish Parliament has the power to hold such a consultative referendum.

"The democratic rights of the people of Scotland are paramount," she said.