Guide to the 2023 Review of Parliamentary constituencies | Boundary Commission for England

Preparing for the review

The Act provides that the electorate figures that are to be used for this review are the Parliamentary electors as they were in the electoral register on 2 March 2020. The BCE has published all the base electorate data for the 2023 Review on its website.
The Act says that the BCE may have regard to ‘local government boundaries’ in developing its proposals. The Act defines such boundaries in England as the boundaries of: counties and their electoral divisions; districts and their wards; London boroughs and their wards; and the City of London. The 2020 Act has now introduced the concept of ‘prospective’ boundaries: this means that the local boundaries we may have regard to are – where applicable – not those actually in place on the operative date of 1 December 2020, but future ward/electoral division boundaries that have been made by Order by that date, but not yet implemented on the ground. The maps published alongside the BCE’s proposals (in hard copy and on the BCE website) will show the relevant local government boundaries.

The Act requires there to be a fixed number of 650 constituencies for the whole of the UK. Having stated that no single constituency may be split between different parts of the UK, the Act ‘protects’ five specified island constituencies (two on the Isle of Wight for England, two for Scotland, and one for Wales), then provides a mathematical formula to determine how many constituencies each of the four parts of the UK should be allocated from the remaining 645, based on the electorate figures as at 2 March 2020. The number of constituencies allocated to England for the 2023 Review is 543 (including the two for the Isle of Wight).
The BCE has subsequently distributed the 541 constituencies (i.e. the total English allocation less the two reserved for the Isle of Wight) between the nine ‘English regions’ defined in the Act. In order to do so, the BCE used the same mathematical formula (commonly known as the Sainte-Laguë method) as that provided in the Act for the initial allocation between the four parts of the UK.

This results in the following allocation of constituencies between the regions:

*Includes the two constituencies for the Isle of Wight

In developing its proposals, the BCE allocates the specified number of constituencies within the relevant region and aims to produce initial proposals in which each constituency is wholly contained within a single region. This approach does not prevent anyone from putting forward counterproposals that include one or more constituencies being split between regions, but it is likely that very compelling reasons would need to be given to persuade the BCE to depart from the region-based approach it adopts in formulating its initial proposals. A description of the extent of each region appears at Appendix C, and maps can be obtained from Ordnance Survey (or viewed on the BCE website once proposals are published).

In considering the procedures for a review, the BCE consults those Parliamentary political parties with constituencies in England on broad issues of policy ahead of the review, in line with its usual practice. Minutes of the 26 November 2020 meeting conducted with the representatives of these parties are published on the BCE’s website.
In formulating its initial proposals for particular areas, the BCE exercises its own judgement and does not consult the Parliamentary political parties, local authorities or any other interested groups or people. The BCE considers that it should take the initiative in preparing its proposals from all the information available to it. The proposals are therefore formed by the BCE from a position of independence and impartiality and are not influenced by any particular viewpoint or opinion. Once the proposals are published, the statutory procedures allow for a public consultation during which political parties and others can then make their views on proposed boundaries known to the BCE.