THERESA May’s former chief of staff has said the democratic mandate for a second Scottish independence referendum is “clear”.

Former Tory MP Gavin Barwell, who now sits in the House of Lords, made the comment in a new book which provides insights into the heart of government during the turbulence of the run-up to Brexit.

He said if the Holyrood election this May had used the Westminster system, the SNP whose manifesto promised a second independence ­referendum would have won 62 out of 73 seats.

Barwell said this means the “democratic mandate” for the question to be asked again “at some point” is clear.

He also said both the damage done to the economy and the risk posed to the Union by Boris Johnson’s hard Brexit deal vindicates May’s attempts to find a compromise over the issue of leaving the EU.

Barwell, who was May’s chief of staff from 2017 until she stepped down as Prime Minister in 2019, is the latest high-profile government figure to dismiss the idea there is no mandate for a second referendum.

His comments were welcomed by a spokesman for First Minister Nicola Sturgeon who said: “The democratic mandate for an independence ­referendum is cast-iron and crystal clear – something that even Theresa May’s former chief of staff has now admitted he agrees with.

“Gavin Barwell’s admission may be uncomfortable for his fellow Tories, but it simply underlines the fact that, whatever their bluster, they know a referendum is coming.”  

In his book Chief Of Staff: Notes From Downing Street, Barwell said he is “uniquely placed” to give an insight into how the country is run –and that the last two years of the May government were among “the most turbulent and important in modern British history”.

He said subsequent events, ­including the “slow realisation” of what Johnson’s Brexit deal means for trade – and “potentially for the future of the United Kingdom” – has prompted a reassessment of May’s years at Prime Minister.

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In the book he states: “We will never know what a no-deal exit would have meant for the future of our United Kingdom, but over the next few years we will discover the consequences of Boris Johnson’s hard Brexit and the omens are not good.

“Support for Scottish ­independence rose from the moment he became prime minister, driven by antipathy to him, opposition to his government’s Brexit policy and the perceived ­relative handling of the Covid-19 ­pandemic by the UK and Scottish Governments.

“Seventy-two of the 129 members of the Scottish Parliament elected in May 2021 stood on a manifesto ­promising a second independence ­referendum.

“If the Scottish parliament was elected using the Westminster ­system, the SNP would have won 62 of the 73 seats.”

As an MP, Barwell previously served as Government Whip and was Parliamentary Private ­Secretary to Michael Gove when he was ­Education Secretary.

He argues the UK Government is on “strong ground” by saying the referendum should not be held now while the focus is on recovering from the pandemics.

BUT he adds: “The democratic mandate for the question to be asked again at some point is clear.”

Since the Holyrood election ­Tories try to downplay a mandate for ­indyref2, despite the SNP and Greens winning 72 out of 129 seats.

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Speaking in an interview ahead of the election, Ciaran Martin (above), who served as constitution director at the Cabinet Office under David Cameron and was one of the architects of the 2014 independence vote, said a referendum should be rerun if there was a majority for pro-independence parties.

He said: “If not this, then what? What’s the legitimate basis on which to resist a second referendum?”

He added he found the UK Government’s position “extraordinary”.

Philip Rycroft, former Scotland ­Office adviser and head of UK governance in the Cabinet Office, has also warned the UK Government’s opposition to indyref2 is not ­sustainable.

In June this year he told the Lords Constitution Committee that ­consent for the Union is “clearly fraying, ­particularly in Scotland”. 

He added: “It’s not sustainable in the long-term to have around 50% of the people in one part of a territory of the UK expressing a wish to leave it.”