Private landlords “are lining their pockets” with housing benefit, the National Housing Federation has claimed.

But the jibe has been denounced by a private landlord body, which said that the money was not a hand-out to private landlords but a support for tenants to pay their rent.

According to the National Housing Federation, private landlords received £9.3m in housing benefit last year – double the amount of ten years ago.

A lack of affordable housing has meant a 42% rise in the number of private renters receiving housing benefit since 2008, says the umbrella body for housing associations. Private landlords received £4.6bn housing benefit in 2006.

If all those in the private rented sector had lived in affordable housing in the last seven years the public purse could have saved £15.6bn, claims the briefing paper.

More than £1,000 a year extra is spent on housing benefit for a family in the private rented sector (£5,705 compared to £4,638 in the social rented sector), the report calculates. That figure goes up to £3,300 more a year in London.

David Orr, chief executive at the National Housing Federation, said: “It is madness to spend £9bn of taxpayers’ money lining the pockets of private landlords rather than investing in affordable homes.

“Housing associations want to build the homes the nation needs. By loosening restrictions on existing funding, the Government can free up housing associations to build more affordable housing at better value to the taxpayer and directly address the housing crisis.”

Nearly double the proportion of families claiming housing benefit are in work (47% compared to 26%) than six years ago, according to the report. Housing benefit recipients renting privately also now earn an average of £4,000 more than six years ago.

The Federation also said homes in the private rented sector “are of lower quality with 1 in 3 failing to meet the English Housing Survey’s Decent Homes Standard”.

But Richard Lambert, chief executive officer at the National Landlords Association, said: “Housing benefit is not a subsidy to landlords, it’s a support for tenants to ensure they can pay for their housing.”

He added that the proportion of landlords letting to tenants in receipt of housing benefit had halved over the last five years because “benefit levels have not kept up with rents”.

“The NHF is clearly still reeling from the news that its members have been ordered by government to reduce spending over the next four years, so it comes as no surprise that they are looking to shift the emphasis and point the finger elsewhere,” Lambert said.

“The private rented sector has grown as the market responds to the increasing demand for homes, particularly from a growing proportion of tenants whom the social sector and housing associations simply are not able to support in the current circumstances.”