Only a small proportion of tenants are likely to be eligible for a mortgage as less than one in five tenants are in full-time employment, said Hometrack.
In the latest Mortgage Market Review consultation paper, the Financial Services Authority highlighted that right to buy borrowers were the most likely to experience arrears or worse repossession.
Hometrack has projected that the right to buy scheme would be unsustainable to maintain as the average capital raised per sale would be £64,725, much lower than the cost of delivering a new property.
The government proposed to reinvest the capital from right to buy sales in new housing to ensure the level of stock does not fall at a one to one ratio.
The one to one replacement would therefore require extra subsidy in the form of low or no cost public land or a reliance on right to buy sales of above average value property which would deliver a higher capital receipt per sale.
Richard Donnell, director of research at Hometrack, said: “The analysis shows a likely shortfall in the capacity of the proposals to deliver a one-for-one replacement rate for right to buy sales.
“Under the new proposals, the government will increase the discounts available with the aim of making it more attractive for some two million plus social tenants in England to buy the home they live in.
“At the same time, the proposals are for all proceeds from these sales to be ploughed back into building new homes.”
