Constituencies

2.3The Parliamentary Constituencies Act 1986, s 11 provides that for parliamentary elections, there shall be the county and borough constituencies, each returning a single Member, which are described in Orders in Council made under that Act.

The same Act provides for four permanent Boundary Commissions, one each for England, Scotland, Wales and Northern Ireland. Each Boundary Commission keeps under review the representation in the House of Commons of the part of the United Kingdom with which it is concerned, though Parliament has periodically varied the frequency of such reviews and the criteria to which they are to accord primacy.

The Parliamentary Voting System and Constituencies Act 2011 amended the 1986 Act, so that boundary reviews were to take place on a five-yearly basis from 2013; gave primacy to the equalisation of the size of constituencies in such reviews; and provided that there should be 600 constituencies (rather than the 650 at the 2010 election) with a committee to review the effect of the reduction, to be established in 2015. In April 2013, the boundary review due that year was postponed to September 2018, and the proposed review of the effects of the reduction in the number of constituencies was postponed to 2020.2

The reduction in the number of constituencies was effectively reversed by the Parliamentary Constituencies Act 2020, which specified that there should be 650 constituencies; required a boundary review to be completed by 1 July 2023; and required subsequent reviews to be completed by 1 October 2031 and every eight years thereafter. The May 2024 general election was the first to be contested on the boundaries determined following the 2023 review.

The Speaker is nominated Chair of each Commission but all other Members of the House of Commons are excluded from membership of a Commission.

Under the Parliamentary Constituencies Act 2020, the Boundary Commissions submit their reports to the Speaker of the House of Commons and send a copy to the Secretary of State. The Speaker must then lay them before Parliament. After all four reports have been laid before Parliament, the Secretary of State must submit to His Majesty in Council a draft of an Order in Council giving effect to the recommendations of the four Boundary Commissions. The draft of an Order in Council must be submitted to His Majesty as soon as reasonably practicable and within four months of all four reports having been laid before Parliament. If the draft Order in Council is not submitted within four months, the Secretary of State must lay a statement before Parliament specifying the exceptional circumstances.

Modifications, to correct any errors they find, can be proposed by the relevant Boundary Commission before a draft Order in Council is submitted to His Majesty. Such modifications must be given effect in the draft Order in Council that is submitted to His Majesty.

Once the draft Order in Council is submitted to His Majesty, His Majesty in Council may make an Order. Parliamentary approval of the Order is not required. The Order in Council has no effect until after the dissolution of the existing Parliament.3

The Parliamentary Constituencies Act 1986 provides that the validity of any Order in Council purporting to be made under the Act shall not be called in question in any legal proceedings whatsoever.4

Footnotes

  1. 1. That Act consolidated the House of Commons (Redistribution of Seats) Acts 1949 to 1979. The 1949 Act substantially re-enacted the provisions of the House of Commons (Redistribution of Seats) Act 1944 (which implemented the recommendations of a Speaker’s Conference earlier that year) so far as concerned the creation of Commissions for the regular re-examination of constituency boundaries. Previously, such Commissions had been set up ad hoc, consequential on a change in the franchise.
  2. 2. Electoral Registration and Administration Act 2023, s 6.
  3. 3. For previous arrangements for implementing Boundary Commission reviews and the repeal of provisions to transfer the functions of the Boundary Commissions to the Electoral Commission, see Erskine May (25th edn, 2019), para 2.3.
  4. 4. Section 4(7). For actions under superseded legislation, see Erskine May (24th edn, 2011), p 21, fn 11.