Nicola Sturgeon has announced plans to hold a second independence referendum, insisting a ballot on leaving the UK is necessary to allow Scotland to choose its own course and avoid a hard-line Tory Brexit.
The First Minister confirmed she is to seek the approval of MSPs at Holyrood next week to start negotiations with the UK Government on a deal that would allow a legally binding ballot to be held.
That could see a second independence vote take place as early as autumn 2018 - just four years on from when Scots voted by 55% to 45% to stay part of the United Kingdom.
It comes after nearly two-thirds (62%) of Scots opted to stay in the European Union in June 2016, but the UK as a whole voted for Brexit.
Within hours of that result being known, the SNP leader said another referendum was "highly likely".
Speaking at her official residence, Bute House in Edinburgh, the First Minister said: "I will now take the steps necessary to make sure that Scotland will have a choice at the end of this process - a choice of whether to follow the UK to a hard Brexit or to become an independent country, able to secure a real partnership of equals with the rest of the UK and our own relationship with Europe."
Ms Sturgeon said she would go to Holyrood next week and "seek the authority of the Scottish Parliament to agree with the UK Government the details of a Section 30 order - the procedure that will enable the Scottish Parliament to legislate for an independence referendum".
She stated: "If Scotland is to have a real choice, when the terms of Brexit are known but before it is too late to choose our own course, then that choice must be offered between the autumn of next year, 2018, and the spring of 2019."
A UK Government spokesman argued a second Scottish independence referendum would be "divisive and cause huge economic uncertainty at the worst possible time".
He said: "The Scottish Government should focus on delivering good government and public services for the people in Scotland."
The spokesman insisted: "As the Prime Minister has set out, the UK Government seeks a future partnership with the EU that works for the whole of the United Kingdom. The UK Government will negotiate that agreement, but we will do so taking into account the interests of all of the nations of the UK.
"We have been working closely with all the devolved administrations - listening to their proposals, and recognising the many areas of common ground, including workers' rights, the status of EU citizens living in the UK and our security from crime and terrorism.
"Only a little over two years ago people in Scotland voted decisively to remain part of our United Kingdom in a referendum which the Scottish Government defined as a 'once in a generation' vote. The evidence clearly shows that a majority of people in Scotland do not want a second independence referendum. Another referendum would be divisive and cause huge economic uncertainty at the worst possible time."
A poll by BMG for The Herald newspaper showed about four in 10 Scots support another vote on independence before Brexit happens.
It suggested that voters are split 52-48 in favour of remaining in the Union.
Meanwhile, an Ipsos Mori poll for STV News that was published just four days ago indicated those who were certain to take part in a second independence ballot were divided 50-50.