The Speaker presides over the House of Commons and is responsible for keeping order during debates and ensuring that the rules of the House are obeyed.

The Speaker must always act impartially and protect the right of all MPs to speak during debates. He or she does not take part in debates and votes only if there is a tie and a casting vote is needed.

The Speaker also represents, or speaks for, the House of Commons in its dealings with the monarch and has the responsibility for maintaining the dignity and privileges of the Commons.

Elected by all members of the House of Commons, the Speaker is a respected senior MP. Once elected, however, the Speaker ceases to represent any political party.

Traditionally, in the event of a general election, the Speaker's seat is not contested - though Betty Boothroyd was opposed by two minor parties in 1997.

Ancient title

The Speakership dates back under its present title to 1377, when Sir Thomas Hungerford was appointed.

Equivalent presiding officers before this time were called parlour or prolocutor, and existed as far back as 1258, when Peter de Montfort is said to have presided over the "Mad Parliament" held at Oxford.

The Speaker acts as chairman during debates, and sees that the rules laid down by the House for the carrying on of its business are observed.

In recent years Speakers have tended to have three spells in the chair: 1430 to 1630, 1830 to 1930, and a period near the end of the day. For the rest of the time, one of the deputies will preside.

Reprimands offenders

It is the Speaker who selects members to speak. He or she acts as the House's representative in its relations with outside bodies, the House of Lords and the Crown.

It is also the Speaker who reprimands any offender brought to the Bar of the House.

The Speaker is also responsible for protecting the interests of minorities in the House.

The Speaker must preserve order in the House.

For instance, an MP who makes an allegation against another member, or uses language which the rules do not permit, may be ordered to withdraw the remark concerned.

In the case of serious general disorder, the sitting may have to be suspended.

In the event of disobedience by an MP, the Speaker can "name" him or her, which will result in their suspension from the House.

Speaker's House

The Speaker has an official residence at the Westminster Bridge end of the Palace of Westminster.

From here begins a formal procession before every sitting of the House, via the Library Corridor, the Lower Waiting Hall, Central and Members' Lobbies to the Chamber.

The Speaker is preceded in the procession by a Bar Doorkeeper and the Serjeant at Arms with the Mace, and followed by the Chaplain, Secretary and Trainbearer.

Black silk robe

On normal sitting days, the Speaker wears a black cloth court suit with linen bands, over which is worn a black silk robe with train.

Betty Boothroyd decided against wearing the full-bottomed wig used by her predecessors.

On state occasions, such as the opening of parliament, he or she wears a robe of black satin damask trimmed with gold, with a lace jabot at the neck and with lace frills at the sleeves.

The Speaker is paid a salary similar to that of cabinet ministers.