Rachel Reeves is planning up to £40billion of tax rises and spending cuts in the upcoming Budget.

The Chancellor told Cabinet ministers that the £22billion black hole she claims the Tories left in the public finances “needed to be filled just to keep public services standing still”.

Officials believe that as much as £40billion will be needed to avoid real-terms cuts to government departments, of which most will need to come from tax hikes, The Times reported.

It comes amid speculation that Ms Reeves could announce more tax rises than those included in Labour’s manifesto in the Budget on October 30.

That manifesto included a promise not to raise taxes on “working people”, including income tax, VAT and National Insurance.

But the Government has faced questions on whether the commitment not to raise National Insurance covered employers’ contributions as well as those by employees.

Sir Keir today declined to rule out raising employers’ contributions, saying Labour had been “very clear in the manifesto that we wouldn’t be increasing tax on working people”.

He added: “It wasn’t just the manifesto, we said it repeatedly in the campaign and we intend to keep the promises that we made in our manifesto.”

Businesses warned that raising their National Insurance contributions would operate as a “tax on jobs”.

In a political Cabinet meeting on Tuesday, the Chancellor warned that the UK’s decline could not be fixed “in one year or one Budget” but said it would deliver on priorities to “protect working people, fix the NHS and rebuild Britain”.

Ms Reeves needs to square the Government’s promises on taxation with a commitment to keep borrowing under control and avoid a return to austerity.

Laura Trott, Conservative Shadow Chief Secretary to the Treasury, said: “In 2021, the Chancellor said increasing employer National Insurance was a tax on ‘workers’. That’s why even in her own words it breaks Labour’s manifesto promise not to increase tax on working people.

“Rachel Reeves herself previously called the move anti-business and we agree, it is a tax on work that will deter investment, employment and growth, and the OBR says it will lower wages.

“Only a day after their first investment summit, the Prime Minister and Chancellor are choosing to sow further uncertainty and chaos for businesses by opening the door to a new jobs tax.”