Scotland should have the right to hold a new referendum on independence if the country is taken out of the European Union "against our will," Nicola Sturgeon, the leader of the Scottish National Party (SNP), said Sunday.

Facing a British referendum on whether to stay in the EU on June 23, Sturgeon used her party's manifesto before the election for the Scottish parliament next month to make clear that she wants another independence vote in Scotland.

There should be such a referendum, she said, "if there is clear and sustained evidence that independence has become the preferred option of a majority of the Scottish people."

"Or if there is a significant and material change in the circumstances that prevailed in 2014, such as Scotland being taken out of the EU against our will," Sturgeon, who leads Scotland's devolved government, said in a statement.

Scots voted 55-45 percent against independence in a referendum in 2014, but Sturgeon's party then won a sweeping victory in a British election in May, taking all but three of Scotland's 59 seats in the Westminster parliament.

The party is expected to be returned to power in the May election in Scotland.

Scottish nationalists have told Prime Minister David Cameron that he cannot rule out giving Scotland another independence vote and that a situation in which Scots voted to stay in the EU but a majority of all Britons voted to leave could be a trigger.

According to polls, Scots are more likely to vote to stay in the European Union than other Britons, and with voters almost evenly split on the EU membership referendum, it is unclear which campaign will win.