<P> Anyone found guilty of high treason may not sit in Parliament until he or she has either completed the term of imprisonment or received a full pardon from the Crown . Moreover, anyone serving a prison sentence of one year or more is ineligible . Finally, the Representation of the People Act 1983 disqualifies for ten years those found guilty of certain election - related offences . Several other disqualifications are codified in the House of Commons Disqualification Act 1975: holders of high judicial offices, civil servants, members of the regular armed forces, members of foreign legislatures (excluding the Republic of Ireland and Commonwealth countries), and holders of several Crown offices . Ministers, even though they are paid officers of the Crown, are not disqualified . </P> <P> The rule that precludes certain Crown officers from serving in the House of Commons is used to circumvent a resolution adopted by the House of Commons in 1623, under which members are not permitted to resign their seats . In practice, however, they always can . Should a member wish to resign from the Commons, he or she may request appointment to one of two ceremonial Crown offices: that of Crown Steward and Bailiff of the Chiltern Hundreds, or that of Crown Steward and Bailiff of the Manor of Northstead . These offices are sinecures (that is, they involve no actual duties); they exist solely to permit the "resignation" of members of the House of Commons . The Chancellor of the Exchequer is responsible for making the appointment, and, by convention, never refuses to do so when asked by a member who desires to leave the House of Commons . </P> <P> At the beginning of each new parliamentary term, the House of Commons elects one of its members as a presiding officer, known as the Speaker . If the incumbent Speaker seeks a new term, then the House may re-elect him or her merely by passing a motion; otherwise, a secret ballot is held . A Speaker - elect cannot take office until he or she has been approved by the Sovereign; the granting of the royal approbation, however, is a formality . The Speaker is assisted by three Deputy Speakers, the most senior of whom holds the title of Chairman of Ways and Means . The two other Deputy Speakers are known as the First and Second Deputy Chairman of Ways and Means . These titles derive from the Committee of Ways and Means, a body over which the chairman once used to preside; even though the Committee was abolished in 1967, the traditional titles of the Deputy Speakers are still retained . The Speaker and the Deputy Speakers are always members of the House of Commons . </P> <P> Whilst presiding, the Speaker or Deputy Speaker wears ceremonial dress . The presiding officer may also wear a wig, but this tradition was abandoned by a former Speaker, Betty Boothroyd . Michael Martin, who succeeded to the office, also did not wear a wig whilst in the chamber . The current speaker, John Bercow, has chosen to wear a gown over a lounge suit, a decision which has sparked much debate and opposition . </P>

Who chairs the debates at the house of commons