Commons Serjeant at Arms is sacked after repeated clashes with Speaker Martin

Major General Anthony Peter Grant Peterkin, the House of Commons Serjeant at Arms for the past three years, has been sacked amid suggestions that he did not see eye to eye with Michael Martin, the Speaker of the House.

One of Parliament's so-called "Men in Tights" - the senior staff involved in the running of the parliamentary estate who still dress in ceremonial garb - the major is responsible for security and the day-to-day management of the Commons.

His contract will not be renewed when it expires later this year and he is expected to leave even sooner, a move that has led to disquiet among senior civil servants. They point to the differences in background between Maj-Gen Grant Peterkin - Ampleforth, Sandhurst, Durham University - and Mr Martin, who is fiercely proud of his background - he left St Patrick's Boys' School in Glasgow at 15, with no qualifications.

While Major Peterkin, the son of a brigadier, has an ancestral home in Scotland, Mr Martin is a former sheet metal worker and trade unionist. The Speaker rarely misses an opportunity to refer back to his upbringing.

When teased by sketch-writers about his performance in the House, he was robust in his response: "I don't wish to change my accent and I am proud of where I was born and brought up."

More than the once it has been suggested that Mr Martin finds it difficult to work with people from upper-class backgrounds, and there was a furore when he fired his diary secretary, Charlotte Every, not long after he took over from Betty Boothroyd as speaker. Two other secretaries, Sir Nicholas Bevan and Roger Daw, have also departed during his tenure.

Major Peterkin, whose stately home is in picturesque Morayshire, was appointed by Mr Martin in 2004 after an outcry at the ease at which "father rights" protesters were able to lob purple flour bombs at Tony Blair as he spoke in the Commons.

His relationship with Mr Martin is said to have deteriorated, however, after the two men clashed over who was to blame for a demonstration in March when Greenpeace campaigners launched a protest from a crane parked close to Big Ben.