Rachel Reeves has been given a £10 billion budget boost by the Bank of England - but the Chancellor of the Exchequer is still expected to press ahead with scrapping winter fuel payments.
Members of her own party are now calling for the senior Labour minister to delay spending cuts, as she is understood to remain firm despite their demands.
Reeves is instead said to be preparing to bank the extra cash, as she looks to sure up her commitments to fiscal discipline and leave herself room to spend it on other projects further down the line, The Times reports.
Labour MP Rachael Maskell blasted slashing winter fuel payments as she said they would raise only a 'tiny proportion' of the £10billion funding the Chancellor has now been given - saying Reeves should 'absolutely' reconsider it now.
She told the broadsheet: 'It's a responsible decision if they have got additional funding. I think there are many demands, but this is most urgent to keep people safe this winter. We've got to do everything we can to keep people warm.
'I would welcome the government delaying so they can properly review this decision and put mitigations in place to keep people safe.'
But a Treasury source responded: 'The chancellor has said there will be difficult decisions across tax, welfare and spending at the budget. Nothing announced today changes that.'
Last month Keir Starmer admitted that the upcoming Budget will be 'painful' - as he defended handing out billions to end strikes by militant unions.
In a downbeat speech from the Downing Street rose garden he warned that October's financial statement - the first by Labour in 14 years - would involve 'short-term pain'.
And earlier this month the true extent of his warnings was shown - as Starmer was cleared to scrap the winter fuel payment for millions of pensioners today despite a Commons revolt.
The Government defeated an attempt to stop it making the handout means-tested to save money by 348 to 228.
A nuclear test veteran who risked his life in Christmas Island atomic bomb tests and has since beaten cancer has further sparked fears as he revealed he worries how he will cope after he was stripped of his winter fuel payment.
Jack Barlow, one of the few soldiers who went through the savage tests in the Indian Ocean to still be alive, is among the 10million pensioners who now have to battle through the season without the extra relief.
The 86-year-old grandfather from Sandbach, Cheshire, now says he and his wife Sylvia, 71, will be relying on blankets as they struggle to pay for their home's payments after he found himself 'just over' the threshold to qualify.
He told The Express: 'I was on Christmas Island seven miles from four atomic bombs. I got a medal last year that was pushed through the letterbox with the rest of the junk and [the axed winter fuel allowance] is the reward I'm getting which I'm really annoyed about.
'I would say to Rachel Reeves that if she was forced to do what I was forced to do, she would change her mind on taking away the winter fuel allowance for all pensioners.'
He added: 'I don’t know what we’ll do this winter. I’m going to have to put more clothing on and wrap up in blankets I suppose. We’ll have to spend less in other ways or not have the heating on because we’ve got to eat. We’ll just have to cut down as much as we can.'
Slamming treatment of atomic testing veterans, he added that the only other reward for his service - his Nuclear Test Medal - was unceremoniously shoved through his letterbox “along with the junk mail” last year.
Just one Labour MP, Jon Trickett, voted with the opposition, but the Government's majority still fell to 120 from its theoretical strength of 167 thanks to 50 more who abstained.
Reeves' extra cash comes after the Bank of England slowed its quantitative tightening procedure, reducing losses to the Treasury through bond sales.
Another Labour MP further hit back at the Chancellor, saying her extra cuts would go down 'extremely badly' after accepting the extra Bank of England funds.
They told The Times: 'It's going to go down extremely badly, not just with Labour colleagues who struggled with these cuts to winter fuel payments, but with our constituents. This is not what a Labour government was elected for.
The approval to cut winter fuel came after a bruising debate, with warnings that panicking old people are planning to ride buses all day and go to bed at 5pm to stay warm.
Cries of 'shame' were heard across the chamber as the result came in.
Earlier, pensions minister Emma Reynolds risked stoking the row by insisting there are 'plenty of very wealthy pensioners' who do not need the handouts - which can be up to £300.
Kicking off the debate in the Commons, shadow work and pensions secretary Mel Stride said Sir Keir's promises of 'integrity' had 'gone out the window' and urged Labour MPs to 'look to your conscience'.
Tories lined up to condemn the decision to strip the benefit from 10million pensioners.
Former minister Esther McVey claimed that Labour has 'declared war on pensioners'.
The Treasury said: 'Decisions regarding quantitative easing and tightening are rightly for the independent Bank of England's monetary policy committee. The overall gains or losses from the asset purchase facility are highly uncertain and predominantly determined by interest rates and gilt prices. The Office for Budget Responsibility will make a full assessment at the October budget.'