Tory former cabinet minister Grant Shapps has joined a growing revolt against Liz Truss’s tax plans, branding her decision to scrap the 45p top rate as “politically tin-eared”.

Mr Shapps, who was transport secretary under Boris Johnson, accused the Prime Minister and Chancellor Kwasi Kwarteng of putting “all their chips on red” in the hope that cutting taxes will deliver growth.

His fellow ex-cabinet minister Michael Gove had earlier said Ms Truss’s plans to pay for vast tax cuts with increased borrowing were “not Conservative” as he threatened to vote against the mini-budget.

The veteran of government, who is influential in the Tory party, said he was “profoundly” concerned about the £45 billion of tax cuts, particularly the abolition of the top income tax rate.

Tory chairman Jake Berry warned that any rebels during a Commons vote on the plans would be turfed out of the parliamentary party, intensifying a row as the Conservative conference began in Birmingham.

Writing in The Times, Mr Shapps said that while he strongly believed in lower taxes, it was not the time for “big giveaways to those who need them least”.

“This politically tin-eared cut, not even a huge revenue raiser and hardly a priority on the prime ministerial to-do list, has managed to alienate almost everyone, from a large section of the Tory parliamentary party taken by surprise to the City traders who will actually benefit,” he said.

“Why? Not least because it is being paid for with borrowed money, the repayment of which is as yet unexplained.”

He described Mr Kwarteng’s mini-budget as “an exercise in what might be called single-entry book-keeping: lots of spending on one side and a blank column on the income side”.

He added: “Tory governments aren’t supposed to do this kind of thing.”

Maria Caulfield, a former health minister and ex-nurse, said she could not support the removal of the 45p rate while nurses were struggling to pay their bills.

She tweeted that if Mr Berry and the party “don’t want this working class MP, fair enough”.

Damian Green, a former deputy prime minister, warned that the Tories would lose the next election if “we end up painting ourselves as the party of the rich”.

Ex-chancellor George Osborne said it was “touch and go whether the Chancellor can survive” the fallout, telling the Andrew Neil Show it would be “curtains” for Mr Kwarteng if his speech on Monday went badly.

Mr Gove welcomed the Prime Minister acknowledging she had made mistakes around the mini-budget, but said she displayed an “inadequate realisation” of the scale of the problem.

He told the Sunday With Laura Kuenssberg show that cutting the 45% income tax rate for the highest earners was a “display of the wrong values” and called for Ms Truss to change course.

The MP even suggested he could vote against the plans in the House of Commons, as Conservative critics eye a possible rebellion.

“I don’t believe it’s right,” he said, when asked if he would vote for the mini-budget when pressed on the BBC One programme.

Ms Truss had earlier admitted she could have been better at “laying the ground” for the plans which sparked a backlash on the financial and mortgage markets.

But Mr Gove said there remained “an inadequate realisation at the top of Government about the scale of change required”.

He said there were two major problems with the plans set out by the Prime Minister and Chancellor on September 23.

“The first is the sheer risk of using borrowed money to fund tax cuts. That’s not Conservative,” he said.

The second, Mr Gove argued, was the move to cut the top rate of income tax and axe the cap on bankers’ bonuses “at a time when people are suffering”.

Mr Gove has wide experience in government, having held cabinet positions under Boris Johnson, Theresa May and David Cameron, and is popular among Tory MPs.

He insisted he was not leading a co-ordinated rebellion of Conservatives but could face losing the party whip if he voted against the tax cuts.

Asked on Sky’s Sophy Ridge On Sunday show whether a rebellion would result in the drastic action, Mr Berry said: “Yes.”

He later told a recording of a Telegraph podcast there should “absolutely not” be a free vote allowing Conservatives to follow their consciences, but said he was “sure colleagues will support the Government”.

Mr Gove used the Telegraph podcast to invite the Prime Minister to reverse her high-borrowing, tax-cutting plans to prevent a rebellion, which he insisted he was not orchestrating.

He told her there was an “opportunity for a course correction and a reset”, adding: “I’ve never voted against the Conservative whip and I want therefore to make sure that we can have a civilised conversation about priorities.”