Edinburgh (AFP) - Scotland's nationalist leader warned on Tuesday that it would be "unfair" for the British government to block another independence referendum, as she asked the Scottish parliament to support her plans for a vote.
First Minister Nicola Sturgeon said British Prime Minister Theresa May must not to stand in her way -- as she opened a two-day debate on a referendum rematch.
May has insisted "now is not the time" for another referendum, while the terms of Brexit have yet to be negotiated.
But Sturgeon told Scottish lawmakers: "For the UK Government to stand in the way of Scotland even having a choice would be, in my view, wrong, unfair and utterly unsustainable."
The Scottish parliament is expected endorse Sturgeon's call for a second referendum in a vote on Wednesday, less than three years after Scots rejected independence in a 2014 referendum.
Sturgeon suggested a re-run could be as little as 18 months away, and by spring 2019 at the latest, before Britain has left the European Union.
Scotland voted strongly to stay in the European Union, as did Northern Ireland, but they were outweighed by England and Wales and the national result last year was 52 percent for Brexit.
"We will allow people to make a genuinely informed choice between being taken down a hard Brexit path or becoming an independent country, able to chart our own course," she said.
- 'Voting blind' -
Sturgeon insists she is open to discussion on an alternative timetable "within reason", but said "it will simply not be acceptable for the UK government to stand as a roadblock to the democratically expressed will of this Parliament".
Scottish Conservative leader Ruth Davidson, May's most senior representative in Edinburgh, confirmed the British government's view that "there cannot be a referendum until people know what they're voting for".
"You don't make a decision on leaving the UK by voting blind," she said.
Sturgeon wants the Scottish Parliament to decide the date, the question, and who will be allow to vote in the referendum.
The SNP does not have an outright majority in the Scottish parliament, but it has already secured the support of the Green party for another independence bid.
Scotland voted against independence by 55 percent in September 2014, but the campaign left the unionist camp politically divided while nationalists flocked to the SNP in droves.
The SNP won all but three Scottish seats in the British parliament in the 2015 general election and Sturgeon was re-elected to the Scottish assembly last May on a pledge to hold another independence vote if Scotland was "dragged out" of the EU against its will.
- Voters sceptical on independence -
Sturgeon is yet to convince a sceptical electorate, with a series of recent polls showing support for independence has barely moved since 2014 -- including a Panelbase poll concluded on Friday which found it stood at 44 percent.
John Curtice, professor of politics at the University of Strathclyde, suggested May's intransigence and the current lack of public support for another referendum may actually work in Sturgeon's favour.
"The 'Yes' side still has considerable ground to make. More time to argue her case might, in truth, be just what Nicola Sturgeon wants," he said.
One of the arguments that helped sway Scottish voters to remain part of Britain in 2014 was the economic uncertainty that would come with independence.
Critics say the situation is now worse, after a fall in oil prices has hit Scotland's energy industry and blown a hole in its public finances.
However, Sturgeon has warned that leaving Europe's single market will causes tens of thousands of job losses in Scotland.