MPs and political parties
Nearly all MPs represent political parties. The party with the most MPs after a general election normally forms the Government. The next largest party becomes the official Opposition. If an MP does not have a political party, they are known as an 'Independent'.
History of the party system
The system of political parties, which has existed in one form or another since at least the 18th century, has become a central element in the working of the constitution and the formation of governments. Since WWII, all but one government have been formed by either the Labour or the Conservative parties.
Parties in parliament
The rules and conventions of the House of Commons allow the government to set the agenda on most sitting days. However, they also recognise the status of the ‘official opposition’ party, which is defined as the largest party (by number of seats) that is not in government.
In practice, the smooth running of proceedings in the Commons relies upon a ‘working relationship’ between the government party and the main opposition party. Typically, party leaders and business managers (whips) from both sides communicate regularly in private to ensure the continuity of business – a process referred to as the ‘usual channels’. Smaller opposition parties may also be involved, depending on their size.
The governing party in the Commons
Up to 95 MPs from the governing party are selected by the Prime Minister to become ministers and join the front benches. These MPs speak on behalf of the government when they are in the Commons. Cabinet ministers and their junior ministers appear in the chamber to make statements, answer questions and respond to debates.
The remaining MPs on the government side are expected to support the government in votes but are generally able to pursue their own priorities. They may be asked to represent their party on legislation committees from time to time and may be elected by the party to serve on one of the select committees of the House.
The opposition party in the Commons
The main opposition party also forms a frontbench team of ‘shadow ministers’, appointed by the leader of the opposition. Their role in the Commons is to speak for the opposition by challenging the government and putting forward their parties’ own policies as alternatives. Opposition spokespeople attend the chamber for all proceedings relevant to their shadow ministerial remit.
The remaining MPs from the main opposition party can pursue their own political priorities but they will be expected to support their party in key votes. As party members, they will be asked to serve on legislation committees from time to time and may be elected to serve on one of the cross-party select committees of the House.
Smaller opposition parties
The second largest opposition party is normally taken into consideration when the chairs and seats of committees are allocated. Their spokesperson may also be called at Question Times and at set-piece debates in the House.
MPs who are members of minor opposition parties, or who are independents, usually have less say in the organisation of the House’s business and no automatic seat on a committee. However, the Speaker ensures that, where possible, MPs from all parties are represented in debates.
Where do MPs sit in the Commons?
MPs from the same party tend to sit together in the House of Commons chamber. The chamber is a rectangular shape so the government and the opposition can face each other. The government sit on the benches to the right of the Speaker. The official opposition sit on the benches to the left of the Speaker.
Ministers and shadow ministers occupy the front benches on either side and are known as frontbenchers. MPs who are not ministers or spokespeople sit behind them and are known as backbenchers.
MPs from other parties usually sit together in groups on the opposition side of the chamber, further away from the Speaker (‘below the gangway’).
'Crossing the floor'
This term is used to describe an MP who changes their party allegiance.
It comes from the fact that, traditionally, MPs from opposing parties sit on opposite sides of the chamber. Therefore, a MP who changes party must usually cross the floor of the House to sit on the other side of the chamber.
More information on these topics can be found in the House of Commons Library briefings: