Michael Martin, the Commons Speaker, was last night accused of adopting the "airs and graces of the ancien regime" after it emerged he spent almost £22,000 of taxpayers' money on libel lawyers to counter negative press reports.

The services of top City lawyers Carter-Ruck during June, July and August came to £21,516 and followed a string of articles questioning his impartiality and conduct.

Erroneously dubbed "Gorbals Mick", Mr Martin, 62, the MP for Glasgow North East, has fallen foul of certain sections of the press, who have highlighted his background as a working-class, former sheet-metal worker from Anderston in Glasgow, who now earns £136,677 a year and lives in a palatial apartment by the Thames.

By contrast, the Speaker's friends point out that coming from a humble background to fill such an august post shows the opportunities open to people in 21st-century Britain.

In 2002, two years after becoming Speaker, Mr Martin retaliated against what his friends branded the "snobbery" of his critics, saying their barbs were "an attack on every working-class person from Clydeside".

However, yesterday the TaxPayers' Alliance accused Mr Martin of treating the public with contempt and adopting "the airs and graces of the ancien regime" over his legal bill. Matthew Elliott, chief executive, said: "By using our money to hire the best media law firm to defend himself against critics and to soothe his thin skin, he's showing contempt towards taxpayers."

He added: "If he wants to hire flunkies, he should pay for them himself."

The Speaker has come in for repeated criticism for his rulings and the exemption of his wife, Mary, from security checks at the Palace of Westminster.

He was also previously attacked for trying to block details of MPs' £5m-a-year travel expenses being published under the Freedom of Information (FOI) Act. The House of Commons Commission, chaired by Mr Martin, spent £17,300 on an unsuccessful bid to block the FOI request.

Certain parliamentary writers have consistently accused the Speaker of favouring his erstwhile Labour colleagues. On one occasion, Mr Martin was accused of bias when he applauded a government decision on asylum policy. In his defence, the MP argued the issue was particularly topical in his Scottish constituency.

In November 2006, the Speaker caused consternation on the Tory benches by ruling a question from David Cameron out of order when he challenged ex-PM Tony Blair over the future leadership of the Labour Party.

The legal expenses emerged after Nick Harvey, the MPs' representative on the commission, disclosed the additional bills.

In a statement he said: "During July and August, the House administration endorsed the Speaker's use of the firm Carter-Ruck to counteract a series of articles which questioned the impartiality of the Speaker. The cost of this advice was £18,696.06."

A spokesman for Mr Martin confirmed the money would come from public funds as would an earlier £2820 bill for work conducted in June.

Norman Baker, LibDem MP for Lewes in Sussex, said: "It appears Carter-Ruck has effectively been used to issue press releases irrespective of the cost to the taxpayer."

A spokesman for Mr Martin declined to comment.