Powers of the Houses in relation to each other

11.7Each House controls its own proceedings and obtains official knowledge of the proceedings of the other only through formal communications (see paras 9.16–9.17 ). Although the former rules of both Houses, which prevented reference in debate to speeches made in the same session in the other House, have been abolished, references to Members of the other Chamber are subject to restrictions (see paras 21.24 and 25.70–25.71 ). Neither may one House summon a Member or a person acting as an officer of the other to appear before it or one of its committees, although Members of one House may give evidence to another if they wish to do so.

The relationship between the two Houses has developed over the long history of the British Parliament. It is formally expressed through a combination of practice, convention and rules (including statutory rules). Practice, for example, governs the proceedings of joint committees (see Chapter 41). The nature and limits of the principal conventions were described in the 2006 report of the Joint Committee on Conventions, Conventions of the UK Parliament. The report considered: the principle of the primacy of the House of Commons; the Salisbury Addison convention (on treatment of manifesto bills in the Lords); consideration of government business in the Lords in ‘reasonable’ time; as well as conventions governing the exchange of amendments between the Houses, on financial privilege, and on secondary legislation. The Committee expressed reservation about the codification of conventions which it considered a ‘contradiction in terms’.1 In 2015 Lord Strathclyde identified a convention that the House of Lords would not vote against secondary legislation, or would do so rarely, and regretted that this convention was ‘now so flexible it is barely a convention at all’.2

Standing Orders on occasion touch upon the relationship between the Houses, for example House of Commons Standing Order No 78(3) in respect of financial privilege and Lords Amendments (see paras 30.11 and 37.21 ).

The Parliament Act 1911, as amended by the Parliament Act 1949, provides a statutory power under which bills which have passed the House of Commons may in certain circumstances acquire the force of law without passing the House of Lords (see paras 16.21 and 30.4930.56 ).3

The creation of the Supreme Court has removed the former concern that the appellate jurisdiction of the House of Lords, abolished by the Constitutional Reform Act 2005, meant judicial determination of the privileges of the Commons would result in the privileges of the House of Commons being determined by the House of Lords.4


  1. Joint Committee on Conventions, Second Report of Session 2005–06, Conventions of the UK Parliament, HL 265, HC 1212, para 279.
  2. Strathclyde Review, Secondary legislation and the primacy of the House of Commons, Cm 9177, December 2015.
  3. The Acts received judicial consideration in the case of R (on the application of Jackson) v A-G [2005] UKHL 56, [20016] 1 AC 262, [2005] 4 All ER 1253, see para 16.21.
  4. See, for example, Stephen J in Bradlaugh v Gosset (12 QBD 271): appeals would lie from the lower court to the Court of Appeal ‘and thence to the House of Lords, which would thus become the judge in the last resort of the powers and the privileges of the House of Commons.’