Nicola Sturgeon caught Westminster off-guard on Monday (13 March) by calling for a second Scottish independence referendum. The first minister of Scotland was expected to make the move at the SNP's spring conference in Glasgow, which starts on Friday (17 March).

But with the Article 50 bill set to pass through parliament on Monday evening and Theresa May expected to trigger EU divorce talks on Tuesday, Sturgeon called the media to her official residence of Bute House in Edinburgh.

"I can confirm today that next week I will seek the authority of the Scottish Parliament to agree with the UK government the details of a Section 20 Order, the procedure that will enable the Scottish Parliament to legislate for a second Scottish independence referendum," she said.

"The UK government was clear in 2014 that an independence referendum should, in their words, be made in Scotland by the people of Scotland. That is a principle that should be respected today. The detailed arrangements of a referendum, including its timing, must be for the Scottish Parliament to decide."

Sturgeon added: "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."

The comments come after an Ipsos MORI poll for STV News, of more than 1,000 respondents between 24 February and 6 March, found that Scottish people likely to vote were split 50/50 on the independence issue. Scots voted 55% against splitting from the rest of the UK in 2014.

But 62% of Scottish voters backed a Remain vote at the EU referendum in June, when the UK voted 52% to 48% to split from the economic and political bloc.

Scottish Labour leader Kezia Dugdale warned that Scotland was "already divided enough". "We do not want to be divided again, but that is exactly what another independence referendum would do," she said.

"Two years ago 85% of Scotland's voters took part in the independence referendum and the result was a clear vote to remain in the UK.

"With our country facing all of the uncertainty around Brexit, the last thing we need is even more uncertainty and division."

However, Labour leader Jeremy Corbyn caused controversy over the weekend by describing a second independence referendum as "absolutely fine".

"Well, if a referendum is held then it is absolutely fine, it should be held," he told the Press Assocation. "I don't think it's the job of Westminster or the Labour Party to prevent people holding referenda.

"I do think we should set it within the context of the economic relationship with the rest of the UK and the question of devolution of EU powers to English regions and to Scotland and to parts of Scotland rather than just to the government in Holyrood, because of the principle of regionalism is it goes to everybody within a region, not just to the central powers and the SNP have a bit of a tendency to centralise everything around themselves."