Michael Martin, the Speaker and a leading figure in the fight against the publication of more detail on expenses, has one of the most generous parliamentary allowances of any MP.

Mr Martin, 62, is chair of the House of Commons Commission, which decided to engage in a legal battle to prevent the publication of a more detailed breakdown on MPs’ expenses. But his own arrangements have been called into question in recent weeks.

Mr Martin, from Glasgow, was a sheet metal worker, became a trade union organiser and entered Parliament for Labour in 1979.

The Speaker receives £137,579 in pay, as well as a grace-and-favour appartment inside the Parliamentary Estate which Commons authorities claim has not been separately valued.

Last month The Times disclosed that his wife, Mary, had claimed £4,280.20 for taxis since May 2004, which were “entirely in connection with household expenditure that supports the Speaker’s duties”. According to the Speaker’s spokesman, she needs to take taxis to shop for food for official functions. The wife of the Speaker has never had a formal role before.

Subsequently it emerged that nearly £50,000 of taxpayers’ money had been spent on providing free air travel for Mrs Martin. She had been given permission to claim travel expenses when her husband became Speaker in 2000. Mrs Martin received £24,485 for foreign flights when accompanying her husband on ten official trips over three years from 2004.

A Commons spokesman said: “The burden on a Speaker’s family can be great at times. When Mr Martin was appointed it was accepted that Mrs Martin was entitled to receive support for certain travel expenses to enable her to support her husband in his official duties.”

The couple’s son Paul Martin has represented Glasgow Springburn in the Scottish Parliament since 1999.

Times Recommends

• Charles blazes trail as sun king
• Thalidomiders win payout 50 years on
• Libel gag on talk of 'medical hurricane'