NICOLA Sturgeon last night warned Theresa May her decision to call a snap election is a “huge political miscalculation” which could strengthen the case for a second independence referendum.

The Tories have just a single MP – David Mundell – north of the Border, and the First Minister said the election on June 8 was an opportunity to further weaken the Tories’ presence.

She accused May, who had repeatedly said she would not call an election until 2020, of an “extraordinary U-turn” and of putting her party before the country in a bid to increase its parliamentary majority of 17.

“This announcement is one of the most extraordinary U-turns in recent political history, and it shows that Theresa May is once again putting the interests of her party ahead of those of the country. She is clearly betting that the Tories can win a bigger majority in England given the utter disarray in the Labour Party,” said Sturgeon.

“That makes it all the important that Scotland is protected from a Tory Party which now sees the chance of grabbing control of government for many years to come and moving the UK further to the right – forcing through a hard Brexit and imposing deeper cuts in the process.”

She added: “In terms of Scotland, this move is a huge political miscalculation by the Prime Minister. It will once again give people the opportunity to reject the Tories’ narrow, divisive agenda, as well as reinforcing the democratic mandate which already exists for giving the people of Scotland a choice on their future.”

May set out her intention yesterday morning to hold the election claiming divisions at Westminster risked jeopardising the Brexit negotiations.

She said she had “reluctantly” taken the decision to go to the country after seeing other parties “playing games” with the process of preparing for the talks.

“Before Easter, I spent a few days walking in Wales with my husband, thought about this long and hard and came to the decision that to provide that stability and certainty for the future, this was the way to do it – to have an election,” she said.

“I trust the British people. The British people gave the Government a job to do in terms of coming out of the European Union and I’m going to be asking the British people to put their trust in me in ensuring we deliver a success of that.”

The campaign will take place at the same time as the Scottish Government has called for a fresh vote on independence to be held, some time between autumn 2018 and spring 2019, to allow voters a chance to decide whether to stay in the UK outside of the EU or be an independent country. The Prime Minister has rejected the demand for a second plebiscite, saying “now is not the time” for such a vote to be held.

May later told ITV News her bid to champion the Union would be a key plank of the Tory election campaign.

“I will be out there championing the cause of a United Kingdom. I believe that we are stronger as a United Kingdom. I think this Union we have between Northern Ireland, Scotland, England and Wales is a very precious Union,” she said.

The First Minister was due to set out the “next steps” in her plans for an independence vote, but those could now be delayed because of the election.

In the 2015 General Election the SNP won 56 of the 59 constituencies north of the border, while Labour, the Conservatives and the LibDems won just one seat each.

Under the Fixed-Term Parliaments Act introduced by her predecessor David Cameron, the Prime Minister will require the support of two-thirds of MPs to go to the country, with a vote scheduled in the Commons today.

In order to call the early election, she will need the support of two-thirds of the 650 MPs in the Commons but Labour is expected to support her, as any opposition would look weak if it did not agree to the chance to take office.

Scottish Green co-convener Patrick Harvie said Scotland’s opposition to leaving the EU “cannot be allowed to fall on deaf ears” in the election.

“I’m sure that voters in Scotland will not allow this election to satisfy the whims of a dangerous hard-right party determined to damage our economy, public services and threaten our EU friends and neighbours who have made Scotland their home. Instead, we must reassert our choice for a fairer and more equal society,” he said.

The Scottish Independence Convention (SIC) condemned May’s snap election announcement and said the only way to protect Scotland from a hard Brexit was “to ensure all 59 Scottish MPs are returned with an explicit mandate to hold a second independence referendum”.

SIC convener Elaine C Smith added: “Once again Scots are being dragged into a Westminster dog-fight that is not of our making and doesn’t fit Scottish political priorities.

“But members of the SIC are ready to mobilise all networks and members to ensure this election creates the opportunity to show Westminster that Scots insist on the right to consider independence again in light of the vast constitutional change set in train by Brexit and the explicit commitments we hope the SNP and Greens will make in their manifestos.

“As Scotland’s First Minister has repeatedly said that second referendum vote should not happen now but once the shape of the Brexit deal is clear.”

Scottish Tory leader Ruth Davidson, Scottish Labour leader Kezia Dugdale and Scottish LibDem leader Willie Rennie underlined their opposition to a second independence referendum in their responses to the announcement.

The Commons vote on whether the election can go ahead will follow a 90 minute debate today, after Prime Minister’s Questions.

May will go into the General Election enjoying the largest poll lead across the UK of any Tory PM in modern history. The Tories currently lead Labour by an average of 17 points. No other Tory Government in modern times has been this far ahead of the main opposition party 51 days from a General Election.