KEIR Starmer is facing a rebellion from his own Cabinet over the extent of the austerity measures planned for the Labour Government’s first Budget.

Even Deputy Prime Minister Angela Rayner is reported to be among the key Government figures to have expressed deep concerns about Chancellor Rachel Reeves’s planned cuts.

It comes after Blooomberg reported that three Cabinet ministers had gone over the Chancellor’s head and written about their concerns in formal letters sent directly to the Prime Minister.

The Times later reported that the ministers in question were Rayner, Justice Secretary Shabana Mahmood, and Transport Secretary Louise Haigh.

Deputy Prime Minister Angela Rayner has raised the alarm about planned cuts (Image: Contributed) One Cabinet minister told that paper that the proposed cuts were “absolutely huge,” as some reports suggested departments could face having up to 20% of their budget slashed.

Reeves told ministers during Tuesday’s Cabinet meeting that plans to fill what Labour calls a “£22 billion black hole” in the UK’s finances will be enough only to “keep public services standing still”.

The Treasury is said to have identified a far larger £40bn funding gap which Reeves will seek to plug to protect key departments from real-terms cuts and put the economy on a firmer footing.

It is with the Treasury rather than the Prime Minister that ministers are said to be largely directing their pushback efforts, as Reeves seeks to finalise her first Budget which she will deliver on October 30.

Experts have argued that ministers need to find £20bn to avoid a squeeze on so-called “unprotected” departments pencilled in by their Tory predecessors, and billions more to prevent a sharp fall in investment spending.

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Some of that could come from changing the measure the Government uses to calculate debt, but economists from the Institute for Fiscal Studies have suggested that some tax rises are all but inevitable to prevent cuts to day-to-day spending.

Downing Street has denied that Starmer gave the public the wrong impression about the scale of tax rises that would come under Labour.

Asked whether the Prime Minister had misled voters, his press secretary said: “No. So we stand by our commitments in the manifesto, which was fully funded.

“We were honest with the British public, both during the election and since, about the scale of the challenge that we would receive.

“Then, of course, one of the first things the Chancellor did when we came in was do an audit of the books and found a £22bn black hole that the previous government lied about and covered up.

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“So that’s why we have continued to be honest with the British people that there are going to be difficult decisions in this Budget, and that’s because of the mess that the Conservatives left the economy in.”

The news of imminent and severe cuts undermines Labour’s repeated claims that they will not bring in austerity.

Earlier this week, Energy Minister Michael Shanks said that the SNP needed “to look up a dictionary for what austerity means” if they thought Labour were bringing it in.

And Scottish Labour MSP Anas Sarwar has been repeatedly reminded of his pre-General Election comments, made directly to John Swinney: "Read my lips. No austerity under Labour."