Former head of the civil service Lord Bob Kerslake has expressed anxiety over government plans to extend Right to Buy to tenants of social landlords.

He said: “There is significant concern in the Lords with the policy in its current form.

“A number of amendments have been discussed, including replacing the cash discount with an equity loan.

“In London the impact would be truly disastrous. It is set to take something like £5bn out of housing in the capital.”

He was speaking at this week’s Chartered Institute for Housing conference.