Cameron will put himself before Tories' scrutiny panel

It has been suggested if Mr Cameron had kept the loan on his London home and borrowed £75,000 less on the house in Witney, then he could have saved the taxpayer more than £22,000.

However, the Tory leader, insisting his claims had been "reasonable", said this was not true "because I was actually paying out more in interest for my mortgage than I was claiming from the taxpayer and, second, when I did pay down the mortgage (around £100,000) I was then able to claim for some very basic and standard bills. Things like heating and lighting and water."

Asked if he would be going before his party's scrutiny panel, Mr Cameron replied: "Of course, the scrutiny panel looks at ever single Conservative MP."

Last night, Labour's John Mann suggested voters would be "baffled" by the Tory leader's response, saying: "People will find it hard to believe Mr Cameron's decision to arrange his finances so that all of his mortgage debt was on a property funded by parliamentary allowances meant no extra cost to the taxpayer as compared to continuing to share the debt between two properties."

The Nottinghamshire MP added: "It may be embarrassing for him to volunteer to go through his own scrutiny process but simply appearing before an in-house panel that answers directly to him isn't going to convince anyone and wouldn't be good enough."

One Tory MP who could face some tough questions before the Tories' "star chamber" is Eleanor Laing, a Scot who represents Epping Forest in Essex.

Not only could she have to repay tens of thousands of pounds but also her frontbench role as Shadow Justice Minister could be under threat after she supposedly avoided a £180,000 bill for capital gains tax (CGT) on a property on which she made a £1m profit.

Ms Laing argued that, by law, she was obliged to name the London flat as her main home for tax purposes even though she declared it as her second home to the Commons authorities.

Mr Cameron made clear: "I don't think it is right to get money from the taxpayer for what you nominate as a second home and then to sell it and not pay CGT."

The Tory leader appeared not to rule out sacking Ms Laing from the frontbench, adding: "Where appropriate, others will be removed from the front bench if they do not behave appropriately. I want to be tough but I also want to be consistent and fair."

The latest allegations include: David Mundell, the Shadow Scottish Secretary, claimed more than £3000 for photographs and photo equipment. He defended his claims, noting how his constituency of Dumfriesshire, Clydesdale and Tweeddale was one of the largest in the UK and it was "appropriate" to show his constituents he had been in their communities. Last month, he insisted his "conscience is clear" over his expense claims. Charles Kennedy, former Liberal Democrat leader, claimed for boxes of mints and teddy bears from the Commons gift shop to be used in "prizes" for a charity draw but the MP made clear it was a mistake and the £36 bill had been repaid. He successfully claimed £18 for a Remembrance Sunday poppy wreath in 2006, which he again said was a mistake and has repaid the money. An attempt to claim £49 for wreaths in 2007 was turned down. Mohammad Sarwar, Labour MP for Glasgow Central, estimated to have a personal fortune of £16m, claimed £86,000 for a mortgage on a London flat which he paid for from a Swiss bank account. He was unavailable for comment and was said to be in Pakistan opening a charity hospital. Eric Joyce, Labour MP for Falkirk, claimed more than £120,000 for his second home in Croydon even though the person who bought it from him last year insisted it was a tip. Mr Joyce, who claimed the most of any MP in expenses last year of £187,334, denied any wrongdoing and claimed the property was in "perfect spick and span order". He said he made no gain from the property as it was in his estranged wife's name and so did not have to pay the £40,000 CGT as reported. His second home is now a rented flat in London.