Rishi Sunak is facing a growing Tory revolt over plans to axe the weekly £20 increase in Universal Credit.
50 Conservative MPs from Red Wall seats signed a letter to the Chancellor demanding the temporary uplift to the lifeline benefit stays in place until lockdown ends.
Boris Johnson signalled this week that the £1040-a-year increase brought in during the pandemic would end in April as planned.
The Prime Minister told MPs on Wednesday he would "rather see a focus on jobs and a growth in wages than focusing on welfare".
He also claimed “the best thing is to get people into employment" - despite the fact 39% of the 5.7million Universal Credit recipients are already in work.
Labour plans to force a Commons vote on making the uplift permanent on Monday.
The Joseph Rowntree Foundation has warned that the cut could see another 200,000 children pushed into poverty.
The influential Northern Research Group, representing Tories in the North and Midlands, put pressure on Mr Sunak for more support in the Budget in March.
They want the Universal Credit uplift and business rate rebates to continue until lockdown ends, VAT slashed to 5% for businesses in the leisure and tourism sector, and stamp duty abolished for homes under £500,000.
Chairman Jake Berry said: "Lockdowns - although necessary while we wait for the vaccine to be rolled out - only entrench and compound disadvantage already felt by those communities this Government has promised to level up.
"Whilst we welcome the unprecedented support provided by this Government for those impacted by this virus, to relinquish support now would cause long-term damage to large parts of the North and weaken our recovery."
Tory former Work and Pensions Secretary Stephen Crabb tweeted: "Good to see colleagues in the Northern Research Group of MPs join call to extend Universal Credit uplift.
"UC has been especially important in Red Wall seats supporting low wage workers and those losing jobs."
Shadow Work and Pensions Secretary Jonathan Reynolds urged Tory MPs to vote with Labour on Monday, where they are calling for the benefit uplift to become permanent.
“The Government is refusing to scrap the Universal Credit cut in the face of opposition from 50 of its own Northern Research Group MPs, two former Conservative Work and Pensions Secretaries and dozens of charities and campaign groups.
“Britain is facing the worst recession of any major economy because of the chancellor’s incompetent handling of the pandemic.
"Rishi Sunak must end the uncertainty for millions of families and secure our economy by cancelling the cut.
“If he refuses to act, we urge Conservative MPs to vote with Labour on Monday to protect families’ incomes.”
