The main chamber in the House of Commons consists of two sides facing each other Government and Opposition.
MPs who support the Government sit on the Government benches and all other MPs sit on the Opposition benches. The layout thus forces smaller parties on to the Opposition side.
This difference between Government, which decides most of the agenda and ensures that almost all decisions are those that it wants, and the Opposition which opposes and questions the Government is central to the way the British Parliament works, though there are some aspects which blur the edge between the two.
The only exception is the Speaker of the House of Commons and his three deputies who preside over the debates and decisions.
The Speaker has been elected for a constituency as other MPs are and is chosen by MPs to take up the role.
The Speaker decides who can speak, ensures that they keep broadly to what is being discussed, the procedures to be followed and also keeps order, with the power to force MPs to leave if they do not follow the rules.
In all of this, the convention is that the Speaker does not favour any party. They only vote if the result has been a tie and only then according to past rules such as voting down any amendment.
The Speaker is also responsible for the running of Westminster overall and the relationships between Westminster and the outside world. The last Speaker, John Bercow, expanded his role to include promoting education about Parliament.
