Theresa May in Battle to Keep Scotland in UK, Britain Out of EU

Although the In-Out referendum on Britain's membership of the EU, June 23, 2016, ended with 52 percent voting to leave the EU, in Scotland it was 67.2 percent voting to remain, and Sturgeon says she wants a second referendum by the summer of 2019, giving Scotland the chance to leave the United Kingdom and remain part of the EU.

Sturgeon is set to gain the assent of the Scottish Parliament for a second referendum, based on its May 2016 manifesto, which stated: "The Scottish Parliament should have the right to hold another referendum […] if there is a significant and material change in the circumstances that prevailed in 2014, such as Scotland being taken out the EU against our will."

​"If the UK leaves the EU without Scotland indicating beforehand — or at least within a short time after it — that we want a different relationship with Europe, we could face a lengthy period outside not just the EU but also the single market. That could make the task of negotiating a different future much more difficult," Sturgeon said.

"These considerations lead me to the conclusion that 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 should be offered between the autumn of next year, 2018, and the spring of 2019," she said.

However, she was swiftly rebuffed by May, who said "now is not the time" for another referendum, saying that the Brexit negotiations were for the whole of the UK and that holding a referendum would distract from the already fraught negotiating process.

'Great Union'

May is due to tell the Scottish First Minister that Britain will not turn its back on the world as it negotiates Brexit and that Scottish independence should wait until the outcome of the Brexit negotiations, which will see a combined United Kingdom emerge as a global player.

"Indeed, we are going to take this opportunity to forge a more global Britain. The closest friend and ally with Europe, but also a country that looks beyond Europe to build relationships with old friends and new allies alike," she was due to say, according to excerpts of a speech released by her office."

​"And it says this: that when this great union of nations — England, Scotland, Wales and Northern Ireland — sets its mind on something and works together with determination, we are an unstoppable force," she was due to say.