NICOLA Sturgeon is to stick to her timetable to put her demand to the UK Government by the end of December for powers for Holyrood to have a second independence next year – despite a snap election in December.

The First Minister told the SNP conference in Aberdeen this month she would make the request by the end of this year to the UK Government so a new vote could be held in 2020.

But with an election in mid-December the leading political expert Professor John Curtice cast doubt on whether she could stick to her desired timetable.

“The First Minister isn’t going to apply for a Section 30 order at the moment. And convention would dictate the UK government will not make any major decisions until the election is over and any important decisions would have to be made in consultation with the opposition,” he explained.

“There’s no point in putting in a Section 30 order request before Christmas. The election will be mid December, parliament won’t be back until about a week after that and we will just about manage to serve about a week and then it’s Christmas.”

But responding to Sir John’s doubts, the First Minister’s spokesman insisted she would make the request this “calendar year”. He told The National: “As the First Minister has made clear, we will be demanding the transfer of power for a referendum before the end of this calendar year.

Independence will be at the very heart of this election campaign, and another win for the SNP will be an unequivocal and irresistible demand for Scotland’s right to choose its own future.”

Sir John’s reasoning was based on the situation once an election is called Parliament is dissolved and the Government does not make any policy announcements during the election period. Likewise, he said, after polling day there is a period before a new Government is formed and Parliament reconvened during which no announcements are made.

The Christmas holiday period – when both Westminster and Holyrood go into recess – could add further to the delay, said Sir John.

He added if Boris Johnson wins the General Election the Section 30 order request would be refused, but if the result led to a hung Parliament the First Minister would seek a Section 30 order as a condition for SNP support for a Labour government.

“If Boris wins, there’s no point putting in the application as it will be refused. If it’s a hung parliament the First Minister won’t need to send a letter as she will be talking to Jeremy Corbyn about the terms and conditions of supporting a minority Labour government. She can’t write a letter now. No government is going to make such a decision at this point,” said Sir John who suggested it was more likely to be made in January.

Johnson has insisted he will not grant a Section 30 order telling MPs this month the 2014 independence referendum was “once-in-a-generation”.

Labour has said it would not block a referendum though such a vote, it has said, should not happen within the “formative years” of a Labour administration.

However, a recent report by the leading thinktank the Institute for Government said it would be “unsustainable” for the Prime Minister to keep rejecting requests from Scotland for powers to have a second independence referendum if voters backed parties calling for one.

The report said: “If the Scottish people choose to vote for political parties that favour a referendum, then a blanket refusal will not be sustainable.

“If the Union is to survive, it must be because a majority of people in all four parts of the UK are persuaded that its survival is for the best, not because Westminster wields the power of parliamentary sovereignty to hold the nations of the UK together against their will.”

The Referendums Bill, which sets out the framework for a new vote, is going through Holyrood. It is expected to pass its first parliamentary stage next week.

MSPs will then examine it in more detail before a final vote in the chamber. Last weekend the SNP and the LibDems unveiled plans to press for an election on December 9 believing it would be harder for Johnson to win with Brexit undelivered.