The Tory MP says he confident he will be cleared of wrongdoing
A Conservative MP facing claims he used expenses to pay his own company is to stand down at the general election.
David Wilshire referred himself to the Parliamentary Standards Commissioner after reports he directed £100,000 of public money to a company he owned.
His decision followed talks with Tory chief whip Patrick McLoughlin.
Mr Wilshire, who represents Spelthorne, in Surrey, said he was confident he would be cleared of wrongdoing but said he was quitting for the party's sake.
Conservative leader David Cameron has not yet issued a statement.
Mr Wilshire said: "I am confident that he [the commissioner] will confirm that I have done nothing wrong.
"That said, I am very conscious that the allegations and investigation will cause great distress to my family and friends.
"These allegations also run the risk of harming my local party and our national party's chances of winning at the next general election... I have reluctantly concluded that it is sensible for me not to seek re-election next year."
The Daily Telegraph reported that Mr Wilshire had paid up to £3,250 a month in parliamentary office allowances to Moorlands Research Services between 2005 and 2008.
Extra invoices were also submitted and the total paid to the company - owned by him and his partner Ann Palmer - was £105,500.
Mr Wilshire said the firm had closed down last year, but before that it had been included in his entry for the Register of Members' Interests.
He denied any wrongdoing, insisting the arrangement was formally approved by the Commons Fees Office.
The claims were made through office allowances and so have not been examined as part of former civil servant Sir Thomas Legg's review of MPs' second home expenses.
Mr Wilshire has been an MP since 1987 and was returned with a majority of 11,684 at the last general election in 2005.
He is one of more than 100 current MPs who have said they will not seek re-election.