Just one individual in Northern Ireland will be affected by the Government’s controversial benefits cap, an MP has claimed.

Speaking in Westminster, Ian Paisley Junior (right) said he had been told by officials that a single Ulster resident was in receipt of benefits of more than £26,000 a year, and would therefore be the only person affected by the cap.

The Department for Social Development said it was still investigating the effects of the changes, including how many Northern Ireland residents would be affected.

But the North Antrim DUP insisted “I have done my homework,” adding: “These are statistics I have managed to glean from the department.”

His comments came as MPs debated the Welfare Reform Bill last night and repeated concerns were raised about its impact on Northern Ireland.

Earlier Prime Minister David Cameron had been warned by the SDLP’s Margaret Ritchie that working families with disabled children would be affected by the changes.

Speaking during Prime Minister’s Questions, she said: “These are working people who are already facing severe financial difficulties, and the current proposals could cost hard-working families with disabled children and in receipt of the lower disability premium over £1,300 a year.”

Mr Cameron said that transitional arrangements would be put in place so existing claimants did not lose money.

Also speaking during Prime Minister's Questions, the DUP’s Nigel Dodds backed the benefits cap, which will mainly affect households in London.

But he raised concerns about the “disproportionately detrimental” effects of other proposals on Northern Ireland. These include changes to employment support allowance for cancer patients and the reform of the Disability Living Allowance.

Last night, the Westminster government was overturning a string of defeats the Bill had suffered in the House of Lords. They included measures on housing benefit and employment support, a bid to exclude child benefit from the cap and the cuts to disability payments for children.

The Government turned to ancient rules to force the changes through. The obscure device of “financial privilege” was invoked to prevent the Lords delaying the Welfare Reform Bill any further, ensuring it will become law this month.

The Government offered minor concessions, including giving families affected by the cap nine months’ “grace period”, to find a job or move house.