ALISTER Jack has flatly denied claims made in a book detailing the rise of Liz Truss to Prime Minister that he paved the way for her to take over from Boris Johnson. 

The Scottish Secretary was said to have intervened in a dispute that appears to have helped stop Truss from quitting Boris Johnson's cabinet in September 2021.

Out of the Blue, which explores Truss's rise to PM, claims Jack told her to "shut the f*** up" over a policy disagreement or risk losing out on a promotion to a top Cabinet job.

However, Jack has categorically denied these claims reported in The Times – including the phone call – and described the allegations as a third-party interpretation of a conversation that never happened.

The Dumfries and Galloway MP also rejects claims that he offered Truss a more senior cabinet role and used profanities in a discussion with her. 

The biography details the rise and fall of Truss's staggeringly short 49 days in office, written by Harry Cole, the Sun's political editor, and James Heale, the Spectator's diary editor. 

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The authors argued that thanks to Jack's mediation, Truss was able to spend a year at a senior level of government, serving as the Foreign Secretary, and position herself as the alternative to Rishi Sunak if Johnson lost the top job.

The row allegedly centred around Johnson and Sunak's plan to hike National Insurance (NI), a policy Truss and her Chancellor Kwasi Kwarteng would scrap during their short term in office.

Truss, while in post as trade secretary, was suspected of being the cabinet minister who briefed a national newspaper that it would be "morally, economically and politically wrong" to increase NI by 1.25%.

She is said to have made her concerns known to Johnson over the policy which was supposed to pay for social care and deal with the NHS backlog.

The National: Jack remained in post as Scotland Secretary under TrussJack remained in post as Scotland Secretary under Truss (Image: PA)

According to Cole and Heale, Johnson's team was concerned Truss could resign over the policy and devised a "cunning plan".

Jack had become close to Johnson and was reportedly advising him on his Cabinet reshuffle, allegedly contacting Truss to tip her off that she was in line for a significant promotion, the book claims.

However, Jack denies ever contacting any ministerial colleague over the NI rise. 

Shortly after Johnson was warned by Truss that she opposed the policy, the book claims the Scottish Secretary called her to say: “Look Liz you’re gonna get a massive job in two weeks’ time, a massive job. You would be well advised to shut the f*** up.”

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Jack denies this call took place, The National understands. 

A Downing Street official told the book's authors Truss "then sucked it up". 

She was then appointed foreign secretary, with Cole and Heale arguing: “Perhaps Alister Jack’s plan had worked after all; Truss did not resign.”

Cole told The Sunday Times: “For fans of alternative history, the role Alister Jack played in the rise of Liz Truss is fascinating.

“Had he not convinced her to temper her attacks on Johnson and Sunak’s national insurance rise in September 2021, perhaps she would have resigned. Or perhaps Boris would never have promoted her to foreign secretary to clip Sunak’s wings and set up the battle to replace him a year later.

"Keeping her on board made her a contender as she spent a year basically being the alternative to Rishi if Boris did go down so it was clearly a key milestone in her tilt for the top job — and all that followed.”

Ian Blackford, the SNP Westminster leader who attacked Jack last week over reports he is in line for a peerage, said: “I trust that the soon to be Baron Jack will be pleased with himself, if he indeed paved the way for the most disastrous prime ministership in history, leading to soaring mortgage costs and the poorest struggling this winter."

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We previously told how the SNP's shadow constitution spokesperson Tommy Sheppard described reports that Johnson had asked four Tory MPs to delay taking up seats in the House of Lords to avoid triggering by-elections as a "manipulation of democracy".

Johnson asked MPs including Jack and former culture secretary Nadine Dorries to hold off until the next General Election before taking on the peerages after he nominated them in his resignation honours list.