Why does the UK have two Houses of Parliament - the House of Commons and the House of Lords - and what are the main roles of each?


The two-House system used in the UK Parliament is designed to allow both the common people (in the Commons) to have their say on matters through Parliamentary representation, and for the decisions made to be reviewed by peers (in the Lords). In this way the two-chamber system acts as a check and balance for both Houses.

Common Features

Most Bills can be introduced to either House, and most Bills pass through both Houses (sometimes more than once, should the Houses disagree on the Bill) before they go on to gain Royal Assent. Either House can propose amendments to a Bill.

The Commons

Members of the House of Commons are publicly elected by way of General or By-Elections and their role is to represent the people of their constituency.

Members of the Commons (MPs) debate political issues and proposals for new laws. It is one of the key places where government ministers, like the Prime Minister and the Chancellor of the Exchequer, and the principal figures of the main political parties, work.

The Commons alone is responsible for making decisions on financial Bills, such as proposed new taxes. The Lords can consider these Bills but cannot block or amend them.

The Lords

Members of the House of Lords are mostly appointed. They include experts in many fields which are generally used to determine the feasibility of a Bill before them.

The House of Lords complements the work of the House of Commons. It makes laws, holds government to account and investigates policy issues.

The Lords used to have a veto to stop legislation from the Commons gaining Royal Assent. This was reduced by the Parliament Acts to the ability to delay a Bill by up to a year, although there are some types of Bills to which the Parliament Acts do not apply:

  • Bills prolonging the length of a Parliament beyond five years
  • Private Bills
  • Bills which start in the Lords

This enables the Commons to "force through" a Bill which has stalled by disagreements between the Houses.

There are three types of Lords:

  • Life Peers

    Appointed for their lifetime only, these Lords' titles are not passed on to their children. The Queen formally appoints life Peers on the advice and recommendation of the Prime Minister.

  • Archbishops and bishops

    A limited number of 26 Church of England archbishops and bishops sit in the House, passing their membership on to the next most senior bishop when they retire. The Archbishops of Canterbury and York traditionally get life peerages on retirement.

  • Elected hereditary Peers

    The right of hereditary Peers to sit and vote in the House of Lords was ended in 1999 by the House of Lords Act but 92 Members were elected internally to remain until the next stage of the Lords reform process.


Various pages from the UK Parliament website

  • Lords cannot block bills, only amend or delay them. If one house makes revisions it must be sent to the other to approve it or make further revisions until both houses agree on the final document. Bi (not Bye) elections are only held when an MP becomes unable to perform his/her duties. Otherwise it is a a general election when the entire country elects their MPs. The house of lords rarely (I don't think it can) introduces bills, that is done solely by the house of commons. – UKB Dec 5 '12 at 23:15
  • Royal assent is simply ceremonial. The queen theoretically has the power to block it but she would be deposed and as such she does not truly have this power. Principal figures of political parties - not nessisarily. They can sit in lords too. It is generally the leader of the party and the cabinet (or shadow cabinet for the opposition) chosen by the leader of the party that sit in commons. Other senior people in the party such as the chairman may sit in either house and they have whips etc. for the house of lords too. – UKB Dec 5 '12 at 23:18
  • Feel free to edit :) I meant to comment that it was only a first draft – Graham Wager Dec 6 '12 at 9:52
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    @UKB A few points - Lords can block Bills of certain types, my update addresses this more completely. Bye- was incorrect, but so is Bi-, it's actually By- (parliament.uk/mps-lords-and-offices/offices/commons/hcio/…). Bills can be introduced by the Lords (services.parliament.uk/bills/public.html - those tagged with [HL]). As for being deposed, I'm sure it would entirely depend on whether the people generally agreed with her! :) – Graham Wager Dec 6 '12 at 12:23
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    @JonathanReez: It already did, on 7 February 1649 during the English Civil War era. The House of Lords was restored in 1660, along with the monarchy. – Royal Canadian Bandit Jun 27 '17 at 10:01

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