More than 120 Labour back-benchers have placed their names on a “reasoned amendment” designed to halt the Universal Credit and Personal Independence Payment Bill at its Commons Second Reading next week. If the Speaker selects the amendment and the other opposition parties fall in behind it, ministers could lose the vote - an outcome that would stall the flagship welfare overhaul.

The dissenting MPs argue the Bill fails basic tests of fairness and compassion. Their text says it lacks a credible plan to give disabled people personalised help into work, was drawn up without meaningful input from those affected, and rests on flimsy evidence. Departmental analysis, they note, forecasts that 250,000 more people, including 50,000 children, would be pushed into relative poverty. The amendment also warns that tightening functional descriptors will penalise those with fluctuating mental-health conditions or other “non-visible” impairments, undermining dignity and independence.

Downing Street insists there is a “moral case” for change, describing the present welfare model as unsustainable. Measures set out in the recent green paper target savings of £5 billion by 2030 through adjustments to Universal Credit, Employment and Support Allowance and PIP. The Prime Minister argues that without reform future support could collapse altogether.

Disability organisations and anti-poverty campaigners dismiss that narrative. They accuse the government of rushing ahead with austerity-style cutbacks while withholding detail of how assessments will change. With so many unknowns, opponents say few MPs could endorse the legislation in good conscience, warning that once again disabled and working-class households are being told to shoulder the burden.