The chairman of the Commons Standards Committee has stood aside from his post amid an investigation into whether he broke rules by hosting events for a drugs firm.
Sir Kevin Barron has referred himself to the independent commissioner Kathryn Hudson after The Daily Telegraph reported that he received fees for sponsoring dinners and a breakfast on the parliamentary estate.
In a letter to Ms Hudson, the Labour MP insisted that he had done nothing wrong as the money was donated to charity.
"My own understanding is that due to the fact that I made no personal gain and all the fees were paid to a charity, I had not breached the rules on usage of parliamentary facilities for personal or business use," Sir Kevin wrote.
"It is a matter of record that I followed the rules in registering this interest and that I deposited an agreement for the provision of services, as the rules required.
"In light of the allegations that I may have breached House of Commons code of conduct or rules, I refer myself to you for you to consider whether any breaches of the rules or the code of conduct have taken place."
A spokeswoman for the cross-party Standards Committee said Sir Kevin was standing aside from its work "until the matter is resolved".
In June 2011, Sir Kevin reportedly arranged a breakfast meeting for five people in the House of Commons' dining room for the Japanese Pharmaceutical Group. He arranged a dinner for 10 people in the same place later that year, and another dinner for 12 people in July 2013.
House of Commons rules governing hiring rooms for functions and events say that "no part of the venue ... may be used for direct or indirect financial or material gain".
The Commons code of conduct says that "members shall ensure their use of public resources is always in support of their parliamentary duties. It should not confer any undue personal or financial benefit on themselves or anyone else".
Sir Kevin declared his work for the JPS in the Commons Register of Members' Interests, and told the newspaper the firm had made three payments to a charity in his constituency, totalling £9,000.