The Wintertons both represent constituencies in Cheshire
Sir Nicholas and Ann Winterton are to stand down as MPs at the next general election, the couple have announced.
The husband and wife Tory backbenchers said they could not maintain the "hectic pace" of politics and wanted to spend more time with their family.
Sir Nicholas, 71, and Lady Winterton, 68, were judged to have broken MPs' expense rules in 2008 when claiming for rent on a second home owned by a trust.
It is not known if the expenses row featured in the couple's decision.
Sir Nicholas has been MP for Macclesfield in Cheshire for 37 years, while his wife has represented neighbouring Congleton for almost 26.
They announced their retirement in a letter to party leader David Cameron.
Sir Nicholas wrote that the years in politics were "taking their toll" and that the couple feared they were no longer able to represent their constituencies "with the same level of energy and enthusiasm as in the past".
Mr Cameron responded by thanking the couple for their "service, energy and commitment".
Never before had a husband and wife team served the House of Commons for so long "and this is something you can both be very proud of," he said.
Sir Nicholas and Lady Winterton were rebuked last year by Parliamentary Standards Commissioner John Lyon over their claims for rent on a property owned by a family trust.
The couple had transferred their second home - a flat in London, on which they claimed thousands of pounds for rent - to the trust.
At the time, Mr Lyon said that although he accepted the breach was accidental, the couple should have known the claim broke the rules on second home allowances, which had changed in 2006.
Meanwhile, in the current round of allegations about MPs' expenses, the Daily Telegraph claims Chancellor Alistair Darling is among nine cabinet members who used £11,000 of taxpayers' money to pay for personal accountancy advice.
It says he, Jacqui Smith, Hazel Blears, David Miliband, James Purnell, Douglas Alexander, Geoff Hoon and Hilary Benn all claimed for tax return processing.
Mr Darling said he was seeking advice on making sure he paid the right amount of tax.
Macclesfield and Congleton are seen as safe Conservative seats and could see fierce selection battles ahead of the next general election.