The 2013 Periodic Review of Westminster constituencies, also known as the Sixth Review, or just boundary changes, was an ultimately unfruitful cycle of the process by which constituencies of the House of Commons of the United Kingdom are reviewed and redistributed. The four UK boundary commissions carried out their reviews between 2011 and 2013, but their recommendations were not taken up by the government and instead the 2018 Periodic Review of Westminster constituencies was carried out from 2016 to 2018. That review was also not implemented and its results were formally laid aside in 2020.
The boundary commissions were to take into account revised rules for the number and size (electoral quota) of constituencies. The proposed changes included having a total of 600 seats rather than 650, as agreed by Parliament in 2011 to meet a reformist aim of the 2010–2015 coalition agreement.
The process began in 2011 and was intended to be completed by 2013, but a January 2013 vote in the House of Commons stopped the process. The commissions commenced their map-drawing of entirely new boundaries in 2016, before they completed their work in September 2018.
Background
The process was launched on 4 March 2011 by the Boundary Commission for England, Boundary Commission for Scotland, Boundary Commission for Northern Ireland and Boundary Commission for Wales. The changes were to be implemented by virtue of the Parliamentary Voting System and Constituencies Act 2011, which amended the Parliamentary Constituencies Act 1986. Part II of the Act (henceforth referred to as 'PVSaCA') deals with the amendments to the manner in which House of Commons constituencies are formed by the individual boundary commissions. Each commission was obliged to make a final report to the Secretary of State before 1 October 2013 (by virtue of Section 10, Clause 3, which amends Subsection 2 of Section 3 of the 1986 Act).
Following a debate in the House of Lords on 14 January 2013, the Opposition tabled and voted for an amendment to legislation to postpone the date by which the Review ends, which they passed and sent back to the Commons, on a relatively small 69-vote majority. A Commons vote on 29 January 2013 in agreement meant the review instead began after May 2015 for completion in 2018. The Review had been required for completion by October 2013 under the principles of Section 3 of the Parliamentary Constituencies Act 1986 (themselves loosening previous requirements by instead calling for periodic reviews every eight to twelve years) as left intact by Part 2 of the Parliamentary Voting System and Constituencies Act 2011. The Electoral Registration and Administration Act 2013 superseded these principles to make an exception for this Review, delaying it until 2018.
Changes to review process
The original legislation made several significant changes to the way constituencies were to be reviewed.
Number of constituencies: PVSaCA required there to be exactly six hundred parliamentary constituencies (Schedule 2, clause 1) – a reduction of 50 from the total fought at the 2010 General Election. This is the first time a precise number has been included in legislation.
More equal constituencies: with a few specified exceptions for island areas (see below), the size (electorate) of all constituencies must have been within 5% above or below the target number.
Increased frequency of reviews: the first review was to be completed by 2013 so that a general election held in 2015 would have been contested on the new boundaries. The legislation required a review every five years after that date, rather than every twelve to fifteen years as previously. To ensure this timetable was achievable, the reviews would take place over the whole country simultaneously, rather than being phased over several years as in the past.
Protected constituencies
Four island constituencies are 'protected' by PVSaCA. They are:
Orkney and Shetland
(the Western Isles of Scotland) Two seats within the boundaries of the Isle of Wight (this is an enforced division of the single Isle of Wight constituency contested at previous elections)
Timetable
The four commissions adopted consistent procedures for developing their boundary proposals, starting with simultaneous announcements in March 2011 which began the review process.