MPs' expenses will be scrutinised by a new audit body policed by professional, external accountants under emergency plans being drawn up this weekend, it emerged today.

Sir Stuart Bell, the Labour MP for Middlesbrough who is one of those responsible for the current rules governing MPs' claims, said today: "In all probability tomorrow the Commission will approve a special specific audit unit, hived off from the fees office, independent of the fees office which will verify in future every claim that’s made by any Member of Parliament.”

He explained that the plans included hiring professional accountants who were "outside individuals" to comb through and verify new expense claims before signing them off.

Sir Stuart also said that he expected that there will be a statement in the House of Commons tomorrow to apologise to the public over the expenses and second home debacle.

The establishment of a new body to police MP expenses emerged amid a fresh slew of embarrassing expense claims from MPs.

Of those, it emerged today that Kitty Ussher, the Work and Pensions minister, had exploited the lax rules governing parliamentary allowances by carrying out a £20,000 refurbishment of her Brixton home. Even though Ms Ussher had bought the property in South London in 2000 for £273,000, she began claiming for the makeover of the house within a year of being elected and wrote a 12 point letter to the fees office to ascertain how much she could get the taxpayer to cover.

In the letter, she wrote: "The basic situation is that this house was relatively cheap to purchase but requires quite a lot of work. The plumbing in the entire house is strange. There are pipes that are not used. Can we get them removed using the ACA [Additional Costs Allowance]?"

She added: "Most of the ceilings have Artex coverings. Three dimensional swirls. It could be a matter of taste, but this counts as 'dilapidations' in my book! Can the ACA pay for the ceilings to be plastered over and repainted."

When she did file her expenses to the fees office - the body currently responsible for signing them off - she claimed so much in 2006 that she exceeded the £21,634 limit set for MPs. Attached to her expenses was a note: "I am aware this takes us over our limit - please pay as much as you are able!" As a minister, her current salary is £94,228 a year. In the past three years, she claimed more than £60,000 as part of her second homes allowance.

It also emerged today that Tony Blair, the former Prime Minister, remortgaged his constituency home for £296,000 - nearly 10 times its purchase price - just before buying a west London house for £3.65 million. While there is no suggestion Mr Blair broke any parliamentary rules, he was able to use the system to claim for interest repayments amounting to almost a third of the new mortgage on his constituency home. The remortgaged amount was enough to cover the deposit on the new London house. A spokesman for Mr Blair said: “There is nothing new in this story. This is just a recycling of known information from a previous Freedom of Information inquiry. The facts are as we said at the time: there was no cost to the taxpayer in this decision.”

Separately, the former Transport Secretary Stephen Byers received more than £125,000 in second home expenses on a London flat which was actually owned by his partner. Mr Byers claimed a total of £126,648 on the property in Camden, north London between 2001 and 2008. This included more than £27,000 on redecoration, maintenance and appliances over five years.

Five Sinn Fein MPs were also facing questions for claiming almost £500,000 in taxpayer funds to cover the cost of running second homes in London, even though they have not taken up their seats in the House of Commons.

It also emerged that John Gummer, the former environment secretary who served in the Thatcher Government, has used the parliamentary expenses system to claim for moles to be removed from his garden in his Suffolk home. Mr Gummer claimed £9,000 a year for gardening, of which £100 was spent in one year for treating moles. Mr Gummer - who became notorious during the BSE crisis in the 1980s for allowing his daughter to be photographed eating a beef burger - has a £60,000 mortgage on his Suffolk grange and claimed £200 a month to pay off interest on the loan, but also more than £20,000 every year from 2004 on other expenses.

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