Mr Curry is one of many MPs to face an inquiry into his expenses
The head of the Commons standards body has stepped down pending an inquiry into his own expenses - a few weeks after being appointed.
The Daily Telegraph alleged Tory MP David Curry claimed nearly £30,000 for a second home that his wife had barred him from using after he had an affair.
Mr Curry admitted the affair but said reports his wife had banned him from the home were "akin to Harry Potter".
He said he used his cottage "to carry out my duties as a constituency MP".
But he said he would refer himself to Parliament's standards commissioner John Lyon and step down while he investigated.
Mr Lyon's reports are passed to the Standards and Privileges Committee - of which Mr Curry was elected chairman last month - to recommend punishment, where necessary.
Mr Curry said he was willing to share any information with the Parliamentary commissioner, adding: "I am not expecting to end up in the Tower of London."
According to the Daily Telegraph, Mr Curry's wife asked him not to use the cottage in his Skipton and Ripon constituency, in North Yorkshire, after she discovered five years ago that he had had an affair.
But challenged over the allegation, Mr Curry said: "That's akin to Harry Potter. I have stayed in it hundreds, if not thousands, of times.
"I have had the house since 1987, I have not bought it on a speculative whim."
The Daily Telegraph alleged that since 2004 Mr Curry had claimed £28,078 towards the cottage but usually stayed at a Travelodge when he was in his constituency.
Mr Curry told the newspaper he sometimes used the Travelodge because he represented a large constituency and it was sometimes more convenient.
He told the newspaper he had used the cottage "less intensively" in the past four years "because I preferred, if possible, to get back to my family home."
He also said it had been uninhabitable for seven months last year because of damage caused by damp and between 2006 and 2008 had often stayed with his father, who was terminally ill.
MPs' use of their second homes allowance has been at the heart of the expenses scandal - the allowances system is set to be overhauled following a six-month inquiry.
Many MPs have faced accusations they have made unreasonable claims under the old additional costs allowance, which allowed them to recoup up to £24,000 each a year for the costs of running a second home.
Several have referred their own cases to the Parliamentary Commissioner for Standards, who investigates complaints then refers his findings to MPs on the standards committee who decide what action to take.
In recent months, it has asked two former ministers, Jacqui Smith and Tony McNulty, to apologise to the House of Commons over their use of the controversial second homes allowance.
But Mr Lyon cleared Tory MP Alan Duncan and the standards committee had warned against MPs referring their own cases to the standards commissioner.
"Investigations of this kind cost public money and can divert resources away from other work. We will not allow the commissioner's office to be used by members simply as a means of refuting unfounded allegations that appear in the press," the committee said.
Mr Curry, a former minister in the Major government, was first elected to Parliament in 1987.