Nicola Sturgeon has said that autumn next year would be the “common sense" time for a second Scottish independence referendum in the clearest signal yet that she is to demand a vote be staged before Brexit.

The First Minister said a rerun of the 2014 referendum should take place within the “window” that the terms of the UK’s deal with the European Union become “clear”.

A "divorce" agreement is expected to be reached with Brussels within 18 months of Article 50 being triggered this month and Ms Sturgeon argued that Scots could then decide if independence was “the road we choose to go down”.

In a direct warning to Theresa May, she said she was not bluffing and attacked politicians in Westminster “who think Brexit and all of this is some kind of game.”

But the UK Government and Ruth Davidson, the Scottish Conservative leader, said Scots do not want another referendum and argued her comments were “deeply irresponsible”.