Tony Mcnulty had been targeted by campaigners to oust him.
Two London Labour MPs criticised in the expenses scandal have lost their seats in the general election.
Ex-employment Minister Tony McNulty lost Harrow East and health minister Ann Keen lost Brentford and Isleworth The Conservatives picked up both seats.
Mrs Keen's husband, Alan Keen, held on to his north London seat of Feltham and Heston with a comfortable majority.
Tory Richard Ottaway, also named in the expenses row, held Croydon South with a 1.1% fall in support.
Tony McNulty was defeated in the north London constituency of Harrow East, with 18,032 votes to Conservative Bob Blackman's 21,435.
Mr Blackman praised the outgoing MP's service to the constituency but said: "People were annoyed by the expenses fiasco and determined to question whether he should be re-elected."
Alan and Ann Keen claimed £140,000 in expenses
The former minister, who had claimed £60,000 in expenses on his parents' home and more than £2,000-worth of accountancy bills, had been among six MPs targeted by campaign group Power 2010 to prevent them securing a further term after the expenses scandal.
His Labour colleague, Ann Keen, who had also been targeted by campaigners, lost the west London seat of Brentford and Isleworth in a 6% swing to Conservative opponent Mary Macleod.
The former health minister and her husband had claimed £140,000 in expenses for a second home just 10 miles away.
Ms Macleod said: "A lot of people want more open politics and more open politicians."
However, Mrs Keen's husband, Alan Keen, managed to hold his nearby constituency of Feltham and Heston.
But his share of the vote was down 4.5% to 43.6%, and there was a 4.8% swing to the Tories.
Conservative MP Richard Ottaway, whose claims included £102 on coal and £122 for chimney sweeping at his second home, was returned in Croydon South with 50.9% of the vote.