Less than five per cent of Camden residents hit by the bedroom tax have moved into smaller homes and an added 10 per cent have fallen into rent arrears, according to new figures.

Council officers revealed in a report to cabinet that of the 1,944 Camden households affected by the government change to housing benefit on the day it was introduced – exactly a year ago on Tuesday – only 89 (4.5 per cent) have since downsized.

The stated aim of the policy was to tackle under-occupancy of homes subsidised by the taxpayer by encouraging social housing tenants to move out of homes with spare bedrooms.

The removal of the “spare room subsidy” – dubbed the bedroom tax by critics – was one of a number of benefits changes introduced by the government on April 1, 2013.

Social housing tenants deemed to have one spare bedroom have had their housing benefit reduced by 14 per cent, while those with two or more spare bedrooms faced reductions of 25 per cent.

The government claims the policy is saving the taxpayer £1million a week, but Camden Council’s cabinet member for finance, Cllr Theo Blackwell, insists it is a “pernicious” policy which has ultimately failed.

“It’s a total failure,” he said. “It set out to deal with the issue of under-occupancy and, as we warned at the time, people would be unable to move because there aren’t the places to move to.

“People on modest and low incomes are caught within a trap where they are being forced to pay more in rent because of the change in policy, and the change of policy has totally failed.”

The council’s report also showed that an extra 10.9 per cent of households affected by the changes have fallen into rent arrears since the bedroom tax was introduced.

According to the figures, just over half the 1,153 Camden households hit by the bedroom tax, as of early February, are in arrears – averaging £566.

Cllr Claire-Louise Leyland, leader of Camden Conservatives, said: “If they knew they were going to fall into arrears, why didn’t they move? If I didn’t have the money to pay my rent, I’d move.”

The option for families to downsize and move to properties outside of Camden is available, an option the council claims has been taken up by 92 households since the bedroom tax changes.

Cllr Leyland said the bedroom tax “was always going to be a longer-term policy” and will enable increased numbers of families to downsize over time, as properties become available.

Camden Liberal Democrat leader Cllr Keith Moffitt criticised the council for not using all of a £1.6million government grant allocated specifically to support residents affected by the bedroom tax over the last year.

“The council could do more to help because there are these discretionary payments which it seems Camden has underspent by almost £600,000,” he said.

Cllr Blackwell said the council was required to return any of the annual discretionary fund not spent by March 31 and that the authority had needed to reserve some of the fund for any late applications from residents.

A Department for Work and Pensions (DWP) spokesman said it was “absolutely necessary that we fixed the broken system” and that councils have access to £345m to support people affected by the changes over the next year, including “a £20m fund Camden Council did not apply for”.