Thousands of Universal Credit claimants are having 40% of their benefit deducted to pay back outstanding debts.
Labour MP Ruth George said the high level of deductions from payments “will see more people with no option but to go into debt”.
The Department for Work and Pensions said there were safeguards to protect benefit claimants from big reductions.
But figures obtained by Ms George show just how many Universal Credit claimants are having major chunks of their benefit deducted every month.
In January, 6% of all Universal Credit full service claims had 40% deducted from their standard allowance, according to figures released in response to a written parliamentary question.