MPs have backed a motion calling for the upcoming cut in Universal Credit to be scrapped, with Conservative MPs ordered to abstain.
There were 278 votes in favour of the motion, with no votes against recorded.
A £20-a-week increase in Universal Credit was introduced last year to help families cope during the COVID-19 pandemic, equating to an extra £1,000 a year for six million families.
But it is due to expire in April, leading to calls for it to be extended as the effects of the virus outbreak continue to be felt.
The outcome of Monday’s Commons vote, which was called by Labour, is not binding on the government.
But it will be seen as an indicator of the strength of feeling over the policy among MPs.
Sir Keir Starmer’s party is calling on Boris Johnson to keep the £20 uplift in place.
Reacting to the vote, Labour’s shadow work and pensions secretary Jonathan Reynolds said: “It is disappointing that the Conservative government refused to vote with Labour to provide families with certainty and secure our economy.
“They can still do the right thing and drop their plans to cut Universal Credit.”
The prime minister ordered his MPs to abstain in the vote, which means not voting for or against the motion.
In a WhatsApp message to Conservative MPs, he accused Labour of “playing politics” with “legislatively vacuous opposition debates”.
But as well as pressure from opposition parties, Mr Johnson is also facing potential unrest in the Tory ranks.
The 65 Conservatives that make up the Northern Research Group have said scrapping the increase would be “devastating” for families.
Addressing the debate, Treasury minister Steve Barclay said the government was “acutely aware” of the hit to the finances of many people due to the pandemic.
“It’s clear that there is a heartfelt desire shared across all sides of the House to support constituents impacted by the economic consequences of COVID,” he said Mr Barclay.
“As a government, we are acutely aware of the harm caused by the crisis to people’s finances including the most vulnerable in our society.
“At every stage of the pandemic, we have striven to support those who have found themselves at the sharp end.”
Mr Barclay said ministers had introduced a range of welfare measures totalling more than £7bn this year, adding that March’s budget would be the right time to set out “future tax and welfare decisions”.
