A key plank of Gordon Brown’s re-election strategy was condemned by members of his own party yesterday as irresponsible, unaffordable and based on a myth.

The Prime Minister’s plan to offer free care at home to the elderly, outlined yesterday in the last Queen’s Speech before the general election, was compared to “an admiral firing an Exocet into his own flagship”.

Lord Lipsey, a former member of the Royal Commission on Long-Term Care, also accused the Government of peddling a “pernicious myth” that people are better cared for in their own homes than in a nursing home.

The measure, aimed at 400,000 of the neediest people, amounted to a “demolition job on the national budget”, he said, as the Government would be forced to cover unnecessary claims made by the better-off. He said that it threatened to undo current work on building a system to help the elderly and those most in need of care.

“I’m not looking forward to the night of the next general election but, if the result goes as I expect, one of the consolations will be that one of the most irresponsible acts to be put forward by a prime minister in the recent history of this country will be swept away with his government,” he added.

Lord Warner, a former health minister, described the care Bill as totally misjudged. “There has been no proper impact assessment, and no data to show how this would work,” he said. “There’s a big question mark as to whether there’s even actually a Bill ready.”

Other peers are known to oppose a Bill that many see as a last-minute, back-of-the-envelope proposal. Mr Brown, criticised by the Conservatives for what they said was a blatantly electoral programme of 15 Bills, faced more attacks from his own side. Charles Clarke, the former Home Secretary, said that the Prime Minister’s attempts to impose political dividing lines was “neither the best way to govern the country nor the best way for Labour to win in 2010”.

David Cameron said that the “biggest omission of all” was the failure to mention MPs’ expenses or the report by Sir Christopher Kelly, the chairman of the Committee on Standards in Public Life. Sir Christopher joined in the criticism, issuing a statement pointing out that party leaders had agreed that his recommendations should be implemented in full. It was disappointing, he said, that the speech failed to address the remit, powers and independence of the new body being established to regulate expenses.

A Downing Street spokesman said: “We are not standing in the way of any of Kelly’s recommendations. Everything related to sweeping away the old, discredited expenses system . . . can and should be implemented without further legislation.”

The criticisms of the care Bill were echoed by health economists. Niall Dickson, of the King’s Fund, said: “These latest proposals seem to have been hastily put together and appear to cut across the options set out in the Government’s own Green Paper.”

Times Recommends

• The Olympics: you need brass to go for gold
• The new must-have accessory: 3-D specs
• Does Dame Helen Mirren need a Face Lift?