Private landlords received £9.3bn last year in housing benefit, according to new research from GMB.
The analysis, published as the Conservatives announced they would extend right to buy to housing association properties, reveals that 38% of private rented accommodation is paid in part or full by taxpayers.
A GMB investigation in Wandsworth found that of the 15,874 dwellings sold under right to buy, 6,180 are now owned by private landlords who rent them to private tenants.
Paul Kenny, GMB general secretary, said: ‘A GMB investigation in Wandsworth laid bare the harsh reality of the exploitation of our social housing stock. Exactly the same will happen now that the Tories have opened to door to buy to let landlords on housing association properties.’
GMB said the policy had become a charter for the ‘exploitation' of social housing stock for private profit.
‘While tens of thousands of ordinary London families are unable to find council house to rent rich farmers and the elite are scooping them up by the tractor load. The “right to buy" has turned into a rich harvest for greedy farmers,’ Mr Kenny added.