An increasing number of elderly people face the prospect of losing "almost all of their wealth," the government has admitted.
A review of the social care system recommended a £35,000 cap on the amount paid towards a nursing home.
But joint evidence from the departments of Health, Work and Pensions, and Communities and Local Government said they are "unable to commit" to the £35,000 cap.
A submission to a House of Lords committee investigating the ageing population, reported by the Daily Telegraph, said: "At this time, the Government is committed to reducing the structural deficit, and we are unable to commit to introducing a new system.
"This leaves those with some wealth with the risk that they could lose almost all of it, if they need care."