Chancellor Rachel Reeves has defended her decision to scrap winter fuel payments for around 10 million pensioners.
She told the BBC she had found a “black hole” in the public finances and “had to act” to “fix the mess”.
Ms Reeves accused the previous government and former chancellor Jeremy Hunt of hiding a massive shortfall in public money.
But Mr Hunt said the numbers had been available to Labour, and that he was “angry” about the “political exercise” the government was engaged in.
A fierce row between Labour and the Conservatives has broken out after the government said it had uncovered a £22bn hole in the public finances.
Ms Reeves said she had made “tough decisions” based on this position, which have included announcing that from this autumn, pensioners in England and Wales not on pension credit or other means-tested benefits will no longer get winter fuel payments worth between £100 and £300.
She said she had to make the decisions because of the previous government’s “deeply irresponsible” overspending, and that Mr Hunt covered up the true state of the public finances when he was chancellor.
“They were not decisions I wanted to make, they were not decisions I expected to make, but when confronted with a £22bn black hole, I had to act,” she told the BBC, adding that she had “to fix the mess left by the previous government”.
But Mr Hunt has disputed this, and has written to Cabinet Secretary Simon Case to complain about what he sees as conflicting claims made by officials about the “black hole” which risked “bringing the civil service into disrepute”.
He said either spending plans put before parliament earlier this month were wrong, or figures announced on Monday were.
Having been accused of “profligacy” by Labour in the Commons on Monday, Mr Hunt told the BBC he had been made “angry” by Labour’s “political exercise”.
“The fact is, there are pressures in public finances, we had good plans to deal with them: productivity, welfare reform, the Rwanda scheme to deter illegal migrants.”
He said the new government ditching those plans had actually caused the hole in finances.
“It is a decision Rachel Reeves herself made,” he said.
Former pensions minister Baroness Ros Altmann told the BBC she was unhappy at the decision to scrap winter fuel payments.
“I’m shocked that the chancellor has chosen to take money away from some of the poorest people in this country,” she said.
Roughly 850,000 households who are eligible to receive pension credit don’t actually claim it, according to figures released by the Department for Work and Pensions last year.
Baroness Altmann said many people do not claim because they are “too proud” to do so.
Ms Reeves said pension credit would be merged with housing benefit so more people claim who are entitled to it, and the government would work with older people’s charities and local government to increase take-up.
