Enough affordable rented homes to house the population of Oxford have been sold off in England under the Government's Right to Buy policy in the last five years, it has been revealed.
The Local Government Association (LGA), which represents councils, is also warning that only a third have been replaced - leaving a dwindling supply of council homes at a time of rising demand.
Now, the councils are calling on the Government to allow them to rapidly increase borrowing to build and embark on a programme of council house building on a scale not seen in 50 years.
In Birmingham, between 2011-12 and 2015-16, a total of 2,021 tenants bought their council houses under Right to Buy.
Over the same period, the city council has built 1,430 homes through its Birmingham Municipal Housing Trust organisation.
But Birmingham is one of the UK's best-performing authorities on council house building - and even it is failing to replace one-for-one its dwindling stock of council homes.
Since 2012, a total of 54,581 homes have been sold off and just 12,472 replacement homes started, leaving a shortfall of 42,109 homes - enough to house 168,000 people if each home included four family members.
That is equivalent to the population of Reading, Canterbury or Oxford.
At the moment, councils are only allowed to keep a third of the money raised from house sales to reinvest in new building.
But the LGA is calling on the Government to use the Autumn Budget to allow councils to keep 100 per cent of Right to Buy receipts and have more freedom to borrow in order to invest and set rents, as well as the flexibility to determine how they implement Right to Buy policy locally.
Coun Martin Tett, the LGA's housing spokesman, said: "Families around the country desperately need more affordable homes and more routes into home-ownership.
"A model of Right to Buy that actually allows councils to build more homes would vastly increase the opportunities for these families.
"Current Right to Buy arrangements are restricting councils from being able to replace homes being sold under the scheme.
"Right to Buy will quickly become a thing of the past in England if councils continue to be prevented from building new homes and replacing those sold.
"If we are to stand a real chance of solving our housing shortage, councils need the funding and powers to replace any homes sold under Right to Buy quickly and reinvest in building more of the genuine affordable homes our communities desperately need.
"Alongside the ability to borrow to invest in housing, the Autumn Budget needs to hand councils the ability to retain 100 per cent of receipts from sales, combine those receipts with other funding to build replacements and set Right to Buy discounts locally so they reflect the cost of houses in the area."