ReutersDowning Street has said there are no plans to give further mitigations to pensioners who have lost their winter fuel payment.
Prime Minister Keir Starmer and his cabinet “agreed” on the importance of scaling back the benefit, his spokesperson said.
They said Sir Keir told ministers “tough decisions” were necessary to fix “the foundations of our economy”, at a cabinet meeting.
There is unease among unions and some Labour MPs over the move, ahead of a vote on the policy in Parliament on Tuesday.
The Labour government has a large majority and is expected to win the vote, which has been called by the Conservative opposition.
But with speculation about a potential rebellion by some Labour MPs, the vote will be another early test of the prime minister’s authority, following Labour’s general election win in July.
Ahead of the vote, Chancellor Rachel Reeves is expected to address MPs’ concerns at a meeting of the Parliamentary Labour Party on Monday.
Ms Reeves and Sir Keir insist the cut – worth about £1.5bn – is necessary to fill an alleged £22bn “black hole” in the budget left by the previous Conservative government.
The Conservatives say Labour is exaggerating the state of the public finances to lay the ground for tax rises in the October budget.
The winter fuel payment was a universal benefit, meaning it was paid to all pensioners, regardless of their income or wealth.
The government estimates 9.3 million fewer pensioners will be able to claim the payment of between £200 and £300 a year. Only those on low incomes who receive certain benefits will be eligible.
Charities and many MPs are concerned about those on modest incomes who will miss out.
Age UK estimates the policy will mean about two million pensioners “who badly need the money to stay warm this winter will not receive it”.
But the Social Market Foundation think tank says winter fuel payments go to many well-off pensioners who do not need it and have proposed more targeted support for energy bills.
The vast majority of those eligible will only receive the winter fuel payment if they have first claimed pension credit, a state pension top-up.
The prime minister’s deputy spokesperson said the government would “continue to urge people to check their eligibility” for pension credit and to “support people in making those applications”.
The spokesperson said there had been 38,500 pension credit claims in the last five weeks.
In comparison, there had been 17,900 claims over the five weeks before Ms Reeves announced the payment would only be available to those on certain benefits in July.
The PM’’s spokesperson said this was a 115% increase, but added the campaign to get pensioners to sign up was “ongoing” and there was “still more to do”.
Government figures had suggested there were about 800,000 households who were eligible for pension credit but did not claim it.
Asked if Sir Keir accepted the withdrawal of the payments could lead to deaths of some older people, she said “the focus of the government is ensuring that there is a range of support available to help those struggling with the cost of living and energy bills this winter”.
The spokesperson said the prime minister had been clear “he would always support pensioners” and pointed to the triple lock, a policy that increases the state pension from April each year.
He was being “straight with the public” about the “context of the £22bn black hole” and the need to make sure that support is “targeted”, the spokesperson added.
