Downing Street has accused the Tories of “lying” about the state of the nation’s finances when they were in government.
Former chancellor Jeremy Hunt was among those who “covered up” the huge black hole in the Treasury’s coffers before the general election, a spokesperson for Keir Starmer said.
The incendiary comments came as Rachel Reeves prepares to hike taxes and cut spending to raise £40 billion in the Budget.
Labour has repeatedly accused the Conservatives of leaving £22bn-worth of unfunded spending commitments when they lost the election on July 4.
Addressing the cabinet on Tuesday, the chancellor warned that “the scale of inheritance meant there would have to be difficult decisions on spending, welfare and tax” in the Budget.
Critics have accused Labour of hiding the true extent of the tax rises they were planning in the party’s election manifesto.
But the PM’s spokesperson said: “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 £22 billion black hole that the previous government lied about and covered up.
“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 spokesperson added: “The previous chancellor and the wider government weren’t honest with the public about the promises they were making.”
The chancellor is already under fire over her plans to raise around £17 billion by increasing the employers’ rate of National Insurance.
Critics say that would break Labour’s manifesto pledge not to increase NI, income tax or VAT.
Reeves was handed a rare piece of good news this morning when it was announced that inflation has fallen to a lower-than-expected 1.7%.