Alan Keen MP has refused to reveal the salary paid to his son who has been on the parliamentary payroll working full-time for his dad for the past seven years.

As Mr Keen's constituency manager and senior caseworker, David Keen's salary is paid for by public funds. His duties include organising advice surgeries, managing his father's constituency office and linking Feltham and Heston constituency concerns with parliament.

In light of the recent family payroll scandals surrounding disgraced Tory MP Derek Conway, it was put to Mr Keen that he should reveal his his son's exact salary.

Despite being pressed several times on the matter the Feltham and Heston MP, who had the 15th highest staffing allowance out of the country's 645 MPs last year, would only say that David, who is in his 30s, is paid within the correct parliamentary pay scale for his job. The MP said: "He is paid the same salary as other senior members of staff."

Mr Keen and his wife MP for Brentford and Isleworth Ann Keen claimed the 14th and 15th highest amounts for overall expenses out of 73 London MPs.

The Keen's have also been criticised for claiming £38,500 in allowances for a flat in Covent Garden even though they own a house in Brentford.

John Hunt, Hounslow's Green Party's candidate in the May London Assembly election, said "it would be a welcomed sign of transparency and good faith" if Mr Keen were to reveal how much his son earns from the public purse.

Mr Keen added: "My son could earn more in a different job without question."