Now Beckett is found to be profiting from three homes cash loophole

Chancellor Alistair Darling, Transport Secretary Geoff Hoon and Mrs Beckett, who also attends Cabinet, were accused of renting out London flats while living in grace-and-favour homes and claiming expenses for another home.

All three deny breaching any Commons rules and there is no evidence that they have done so, but they faced calls to repay thousands of pounds they have pocketed for second homes.

Mrs Beckett was given a grace-and-favour home in 18th-century Admiralty House in late 1997 - the first president of the Board of Trade to benefit from such a perk for 20 years.

She is understood to have lived there for just over eight years, after the home had been given a £65,000 refurbishment. She then moved into Carlton Gardens for a year following her appointment as Foreign Secretary in 2006.

Derby South MP Mrs Beckett has claimed £106,000 in expenses for a second home in the six years from 2001/02 to 2006/07. She has also declared in the Commons Register of Members' Interests a flat in London as "residential rented property". Tenants are said to have included Labour MP Gillian Merron and a Home Office civil servant.

Mrs Beckett, who no longer has a grace-and-favour home, said she did not make money from renting out the Westminster flat, and was simply "covering costs". Her spokesman said: "Nothing has ever been done outside the rules of Parliament." She stopped renting out the London flat in February last year after losing her Cabinet post the previous year.

Mr Darling is letting a flat in London while living in Downing Street and claiming the second home allowance for his house in Edinburgh. In 2007/08, the year in which he became Chancellor, he put in a bill of just under £10,000. Like Mr Hoon and Mrs Beckett, he declares that he is renting out the flat. A spokeswoman for the Chancellor defended his claims, saying: "He's got to maintain a house in Edinburgh." Mr Darling is also understood to pay council tax for living in No11 and that the perk is taxable as a benefit in kind.

Yesterday, Mr Darling told the BBC that the recent stream of revelations about MPs' expenses were "damaging" to the Government. "We do need to get an outside examination of this," he added.

He spoke out after Transport Secretary Geoff Hoon was criticised for renting out a London property while living in Admiralty House as Defence Secretary for three years, and claiming about £50,000 in second home allowance for his home in Derby, close to his Ashfield constituency in Nottinghamshire.

Mr Hoon said he had done nothing wrong. He said he was advised to move into the rent-free Whitehall flat when he was Defence Secretary in the run-up to the Iraq war. He said: "I was told unless I went into secure premises I would have to have round-the-clock police protection at my home in London."

David Cameron has vowed to ban ministers from being able to claim for two homes. Lib-Dem leader Nick Clegg said it was "barmy" that politicians could benefit from such extraordinary perks. Lib-Dem MP Norman Baker urged ministers to repay the second home money.