Details of MPs’ claims for plasma televisions, furniture and cleaning bills will be kept secret after Harriet Harman bowed to backbenchers’ pressure to stop expenses claims being published.

MPs are preparing to pass a new law next week that will exempt them from parts of the Freedom of Information Act, meaning that they will never again be forced to publish receipts for their claims, in defiance of an order by the High Court. This would make MPs the only public sector employees with special privileges to protect them from disclosing their expenses.

At the same time, the Speaker’s committee revealed that it had watered down tough restrictions on what MPs could claim for. A new regime was promised after Derek Conway, a Conservative Member, was found to be abusing the system. The plans for rigorous external audits, however, have been diluted and a ban on buying furniture and electrical items has been scrapped.

MPs will be allowed to continue using public funds to buy “white goods”, electrical equipment, sofas, chairs, tables, decoration, cleaning, insurance and security. Controversially, MPs will also be able to claim additional sums on their mortgage for “refurbishment”, plus £25 for each night spent away from their main home, without receipts.

A document from the committee led by Michael Martin, the Commons Speaker, said: “It has been argued that it would be excessively burdensome for Members to have provided receipts for all transactions and that additional costs incurred . . . would be likely disproportionate.”

The Commons had been on the brink of publishing receipts for every claim made by an MP since 2005, on the orders of the High Court last year after losing a two-year battle on freedom of information. The Commons authorities spent hundreds of thousands of pounds scanning about one million receipts. If the new law proposed by Jack Straw, the Justice Secretary, passes, this work will be abandoned and pending freedom of information claims will be nullified.

Instead, expenses data will be published under 26 more general headings, rather than the current 13. These will now be broken down into “fixtures, fittings and furnishings” and “other household costs”, which would not allow detailed scrutiny. The Government has been accused of burying bad news - the announcement came on the day that ministers announced Heathrow’s third runway and compensation for Equitable Life policyholders.

Ms Harman, the Leader of the Commons, failed to mention in her announcement to the House that the scanning of receipts would be abandoned. Instead she presented it as a victory for freedom of information. “The public will have more information than they ever have before,” she said.

MPs threw out tougher rules in July last year when the vast majority of Members – 146 of the 172 – who voted to keep the allowance, described as the “John Lewis list”, were Labour, including 33 ministers.

Norman Baker, the Liberal Democrat frontbench spokesman, said that the cover-up would infuriate voters. “After the fiasco of MPs’ expenses there is a great deal of work to be done rebuilding confidence in the Commons. This simply undermines it again.”

Matthew Elliott, of the TaxPayers’ Alliance, said: “It is an absolute disgrace that the Government are going to such absurd lengths to keep MPs’ expenses secret from the very people who pay the bills.”

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