Frank Field claims the Government have accepted that the so-called "bedroom tax" inflicted deeper wounds on Merseyside’s poor than they originally believed.
Birkenhead’s MP has obtained figures showing Merseyside needed an extra £1m in Government funding this year to cover part of the costs of housing benefit reforms – on top of an initial grant of £4.2m.
Mr Field said this suggested the Government “implicitly accepts” that bedroom tax - or spare room subsidy to give it its official name - had caused even deeper hardship than previously thought.
He demanded: “The Government should immediately abolish this vicious measure.”
In answer to his Parliamentary question, the Government admitted that councils across the country applied for an extra £12.9m in 2013-14 to cover discretionary housing payments, which are means-tested payments that provide temporary help to families struggling to pay their rent.
Mr Field said: “This latest announcement is an acceptance by the Government that the bedroom tax has inflicted a deeper wound on poorer people in Merseyside than they originally believed.
“Rent arrears are soaring across the region and most tenants affected have nowhere to downsize to.
"That’s why it has so far cost the Government an extra £1m in emergency assistance in Merseyside alone to limit the damage.
“And this sum, of course, makes no mention of the human cost which can’t be measured in pounds.”
A Department for Work and Pensions spokesman said:"Taxpayers are being saved more than £1m a day because of the removal of the spare room subsidy.
"We are also guaranteeing a strong welfare safety net is in place with a £345m fund available to councils across this year and next."
Almost 90 local authorities applied for extra financial help to cover discretionary payments in 2013-14.
On Merseyside the breakdown was: Halton £100,000, Knowsley £179,000, Liverpool £350,000, Sefton £205,000, St Helens £90,000 and Wirral £150,000.