PM backs Smith over porn | Members' expenses: the full list | 10 most outrageous MP expense claims

An investigation has begun into a mole who is trying to sell the expenses records of all MPs for £300,000, the Commons authorities disclosed last night.

Sir Stuart Bell, a member of the Commons Commission, told the BBC that the asking price was increasing because of the interest in the subject after the embarrassing details of Jacqui Smith’s expenses claim, which included pornographic films watched by her husband. “We have a pretty good idea of not the person, but the source, and that is a subject of a House of Commons investigation,” he said.

It emerged yesterday that MPs will be given the chance within days to edit receipts submitted to justify their expense claims before they are made public. Details that identify individual suppliers, as well as any items on bills not paid for by the taxpayer, can be blacked out by MPs during the next month, Commons officials said.

MPs opposed to full publication of the receipts say that the information could be used to identify their homes and could put themselves and their families at risk. They will be invited to check receipts submitted for the past five years within days and edit out identifying details. Some plan to use the process to delay release well beyond the planned publication date this summer.

Ms Smith’s claim for pornographic films came to light because her unedited claim – which also included a kitchen sink and a bath plug – was leaked. The Home Secretary was plunged deeper into trouble over her allowances and expenses when the Commons published the amount that each MP claimed in the past financial year yesterday.

The figures showed that Ms Smith billed the taxpayer £22,948, close to the maximum, for her family home in Redditch, Worcestershire, during 2007-08. She justifies the cash by classifying the house as a second home, insisting that her main residence is her sister’s house in London.

Ms Smith’s husband, Richard Timney, who has admitted watching the films at the centre of the latest row, was the subject of a claim of £2,531 for 25 journeys from her constituency to London; MPs are allowed to claim a maximum of 30 such trips by their spouses. She also claimed £485 for eight journeys by other family members and £1,732 for 17 trips by staff. It was not clear whether any of these related to Mr Timney, who is employed as her parliamentary assistant.

Other Cabinet ministers who claimed the maximum amount to stay away from home on parliamentary business last year include Shaun Woodward, the Northern Ireland Secretary, Hazel Blears, the Communities Secretary, Liam Byrne, the Cabinet Office Minister and Geoff Hoon, the Transport Secretary.

Nick Clegg, the Liberal Democrat leader, was another of more than 150 MPs to bill the taxpayer the maximum additional costs allowance (ACA) of £23,083. David Cameron, the Conservative leader, claimed £19,626 to pay the mortgage on his Oxfordshire constituency home.

Among MPs claiming ACA cash for a second home were several husband-and-wife teams, including the Cabinet couple Ed Balls and Yvette Cooper, who together received £24,438; Tory MPs Sir Nicholas and Ann Winterton, who got £35,112; and Labour’s Alan and Ann Keen, who claimed £38,193.

Tony McNulty, the Employment Minister, who has been at the centre of a row over his ACA claim for the outer London house where his parents live, claimed £12,600 in second-home allowances in 2007-08. He said that he stopped making claims in relation to the house in Harrow in January because falling mortgage interest rates made it affordable on his MP’s salary.

Details of MPs’ spousal travel claims released for the first time this year showed that Julie Kirkbride and Andrew MacKay, another Tory MP couple, together claimed £1,800 to visit each other’s constituencies.

The total claimed by 646 MPs in 2007-08 was just under £93 million – about 6 per cent up on the previous year’s figure of £87.6 million. The largest claim in 2007-08 was made by Eric Joyce, the Labour MP for Falkirk, who received expenses and allowances totalling £187,334. The lowest claim was made by Philip Hollobone, the Conservative MP for Kettering, who received £47,737, including only £400 for staffing costs.

Gordon Brown last night wrote to Sir Christopher Kelly, the chairman of the Committee on Standards in Public Life, asking him to speed up a review on the issue, which is not due to report until after the next election. In a move that could spell the end of the second-home allowance, Mr Brown also asked him to consider replacing it with a flat attendance fee.

The Prime Minister acted after receiving a letter from Mr Clegg asking to meet him and Mr Cameron to talk about reform. “The recent scandals make it clear we cannot continue with the current system any longer,” Mr Clegg wrote. Despite the calls for more transparency, Commons officials confirmed yesterday that MPs are about to be shown all the receipts they have submitted during the past five years. Some run to 1,500 pages, according to one senior officer who explained why MPs were being given a month to check through the information.

Most expensive MP

Eric Joyce (Labour, Falkirk) £187,334 in total.

Travel, £40,637, including £21,459 for air travel.

Claims by couples

Ann and Alan Keen (Labour, Brentford & Isleworth; and Labour, Feltham & Heston) £315,282 in total, including £38,193 for second home.

Ed Balls and Yvette Cooper (Labour, Normanton; and Labour, Pontefract & Castleford) £308,185, including £24,438 for second home and £4,105 for family travel.

Andrew MacKay and Julie Kirkbride (Tory, Bracknell; and Tory, Bromsgrove) £283,404, including £45,658 for second home.

Sir Nicholas and Ann Winterton (Tory, Macclesfield; and Tory, Congleton) £210,491, including £35,112 for second home.

Cabinet members claiming full second-home allowance of £23,083

Hazel Blears, Liam Byrne,

Geoff Hoon and Shaun Woodward

The rules

MPs are allowed to claim a maximum additional costs allowance (ACA) of £23,083 for staying overnight away from their main home on parliamentary business.

Inner London MPs receive a supplement of up to £2,812 but may not claim ACA. MPs can also claim for running offices and staffing costs up to a total of £111,844; up to £7,000 on stationery and a £10,000 communications allowance.

MPs can claim for trips between Westminster, home and constituency, and on parliamentary business. Different mileage rates apply for travel by car and motobike and members may charge 20p per mile when using their bicycles.

MPs' spouses, civil partners or children aged up to 18 are allowed up to 30 taxpayer-funded single journeys between London and their constituency or second home. Their employees can make up to 24 taxpayer-funded single journeys from Westminster to the constituency.

Grand total

£92,993,748

Average total

£144,176

All claims for expenses

£86,781,205

Average on expenses

£134,545

All claims for travel

£6,212,543

Average on travel

£9,632

10 most outrageous MP expense claims

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