Jeremy Hunt taunted Rachel Reeves over looming tax hikes by asking if the Chancellor agreed with her own assessment of a “jobs tax”.
The Shadow Chancellor, in his final clash with Ms Reeves, said he agrees with the Labor politician's claim that increasing employer national insurance contributions would “take money out of people's pockets.”
And Ms Reeves, 24 hours before delivering her first Budget on Wednesday, was accused by another Tory MP of orchestrating a “collapse in business confidence”.
Mr Hunt said during Treasury Questions: “There has actually been a lot of common ground between us, for example, when, before the Election, she said raising employers' national insurance was a jobs tax that took money out of people's pockets.
“I very much agree. Does she agree with herself?”
The Chancellor flew back: “The Honorable Gentleman knows better than almost anyone else that there is a £22billion black hole in the public finances.
“That will require difficult decisions. Even in those circumstances, we will do everything in our power to protect the incomes of ordinary working people.”
But in a testy exchange, the Conservative former Chancellor blasted: “We all know why she is inventing this fictitious black hole – 30 times this year before the Election she promised not to raise tax.
“Tomorrow, she is planning the biggest tax raid in history.”
And the senior Labor politician then bizarrely pointed to her own party's years in the wilderness under hard-Left leader Jeremy Corbyn.
She said: “I have always respected the Right Honorable Gentleman. But I think it is important that we do not deny the seriousness of the situation that we face.
“The black hole in the public finances, combined with lashing out at institutions suggests he has got more in common with Liz Truss and Kwasi Kwarteng than we perhaps thought.
“I watched my party lurch to an ideological extreme and deny reality and as a result we spent years in opposition.
“Now the Shadow Chancellor is taking his party down the same path.”
The Chancellor is planning to announce a cut to the earnings threshold at which employers pay national insurance and an increase in the rate of contributions.
Capital gains tax, inheritance tax and fuel duty are also expected to be in her sights.
Meanwhile, the £2 cap on bus fares introduced by the Conservatives will be lifted to save cash.
And Ms Reeves was accused of creating a “collapse in business confidence” by discussing the government's economic inheritance, Conservative former minister Sir Desmond Swayne has said.
He told MPs: “Investment requires a measure of optimism, not the collapse in business confidence that (Ms Reeves) has engineered. She would have done better to stress some of the positives that she inherited, wouldn't she?”
Ms Reeves replied: “It's good to be explained how to do my job by one of the members opposite who crashed our economy.
“£63.5 billion of investment into the UK were announced at our international investment summit, investment in life sciences, investment in data centers and digital, investments in clean energy, because businesses have confidence that this Government is bringing stability back to our economy, and working with businesses to seize the opportunities.
“I am really excited about doing that in all parts of our country and working with businesses to do so.”
And Ms Reeves was urged by MPs to “think again” when it comes to means-testing the winter fuel payments and increasing the threshold for the allowance.
In the Commons, Conservative former minister Dame Harriett Baldwin said: “The living standards of a 90-year-old pensioner on a £13,500 income are falling sharply this winter, as a result of her decision to take away the winter fuel allowance. Tomorrow she has the chance to increase that threshold, will she take it?”
Ms Reeves replied: “(Dame Harriet) will know that because of our commitment to the triple lock that the basic state pension and the new state pension will continue to rise. In fact, this winter the new state pension is worth £900 more than it was a year ago and the new state pension is likely to rise by a further £450 next April.
“Indeed, during the course of this Parliament, because of the triple lock the new state pension is likely to be worth £1,700 more, much more than the value of the winter fuel payments.”
During Treasury questions, Liberal Democrat Treasury spokeswoman Daisy Cooper said “the Government does need to think again”, adding: “Either reverse this cut and make it taxable, or look at, for example, raising the pension credit limit.”
Responding, Treasury minister Emma Reynolds said the government had a “steadfast commitment to the triple lock”.