A major 2011 shake-up of the rules governing how the UK’s parliamentary constituencies are drawn has proved controversial. While the new rules deal with the long-standing issue of substantial inequalities in constituency electorates, they also threaten frequent major disruption of the country’s constituency map. But attempts to square the circle by revising the 2011 legislation seem stalled, and the new rules themselves have yet to result in new constituencies. Charles Pattie, Ron Johnston and David Rossiter offer their view of where we are, and where we should go from here.

Largely unnoticed outside Westminster, an important debate has been going on over how to redraw the UK’s constituency map. The current rules for doing so are enshrined in the Parliamentary Voting System and Constituencies Act 2011 (the Constituencies Act). But since the start of this year, two major proposals have been made to revise aspects of the Act. In February, the House of Commons Public Administration and Constitutional Affairs Committee (PACAC) published a report setting out its proposals (and in late May, the government responded). And a private member’s bill sponsored by Labour MP Afzal Khan, containing a different set of recommended changes is still making its way through parliament.

At the heart of the debate is the need to redraw constituency boundaries periodically. Other things being equal, if each vote is to carry the same weight, then each constituency should contain the same number of electors. But inequalities are inbuilt to the current rules (established in 1944 and only marginally amended since). In particular, Wales is significantly over-represented; at the 2017 general election the average constituency electorate was some 57,500 compared to 67,600 in Scotland, 73,700 in England and 69,000 in Northern Ireland. And there are substantial variations within each country: in Wales, for example, the largest constituency then had 76,500 registered electors and the smallest only 41,400. In addition, the electorate changes at different rates in different places (reflecting variations in local birth and death rates, and migration from one place to another); some constituency electorates grow faster than others, with the consequence that the value of a vote in the most populous constituencies becomes smaller than the value of a vote in less populous places. Hence the need to review the boundaries regularly, to bring electorates back into line with each other as well as – according to the principles introduced in the 2011 Act – removing the in-built variations between and within countries.

Since 1944 redistricting in the UK has been conducted by independent non-partisan Boundary Commissions (one for each of the constituent nations). Before 2011, the relevant legislation enshrined two different principles: the arithmetic (equalising electorates between seats) and the organic (representing identifiable local communities and providing continuity of representation). Neither was clearly defined in the legislation, however, and neither had priority over the other. And until 2011 reviews were relatively infrequent, every 12-15 years; substantial variations in constituency size remained even after a review, and over time those disparities grew.

The Constituencies Act removed much of the resulting ambiguity. It established the clear legal priority of the arithmetic principle (equalising electorates) over the organic, setting tight constraints on variation in constituency electorates. With four named exceptions, all constituencies must have electorates within ±5% of the national average; only within that constraint could the Commissions take other considerations – such as local community ties – into account. It requires boundaries to be redrawn every five years, so that (combined with the Fixed-term Parliaments Act 2011) each election should involve new constituencies. The Act also reduced the House of Commons from 650 to 600 MPs.

The Constituencies Act has not yet changed the constituency map, however. The first review conducted under the new rules should have produced a new constituency map for the 2015 General Election but fell victim to infighting within the Conservative-Liberal Democrat coalition; the 2015 and 2017 General Elections were thus fought using the seats introduced for the 2010 General Election (2005 in Scotland). Revising the constituency boundaries was a manifesto priority for the Conservatives, however (as they tend to be unfairly disadvantaged by aging constituencies), so, having achieved a parliamentary majority in 2015, the government did not prevent a further review that, under the legislation, began in 2016. It must report by October 2018 and if accepted its recommendations will form the constituencies for the 2022 General Election.

By clarifying and standardising the rules for boundary reviews, the Constituencies Act is a substantial improvement over its predecessors although it has been criticised on several grounds. Some (such as the commonly-heard suggestion that it enshrines an unfair pro-Conservative gerrymander) are spurious. We don’t know what the final outcome of that review would have been, as the Commissions had not published their final recommendations when the procedure was halted by parliament. All the evidence is that the Conservatives would have benefited. At the 2010 general election, they won 306 of the 632 seats in Great Britain (i.e. excluding Northern Ireland) to Labour’s 258; under the Commissions’ revised proposals of the 584 seats the Conservatives would have won 302 and Labour 223. However, this was not because of any gerrymandering but very largely because of the equalisation in constituency electorates: the number of Welsh seats was reduced from 40 to 30, for example, and Labour suffered substantially from that.

Other criticisms have more substance. One area of anxiety is the potential for repeated major disruption to the existing constituency map following future reviews. That aborted first review under the new rules would have meant far more substantial changes to the map than at previous reviews. Even constituencies with current electorates within the mandated size limits were not immune to being redrawn: many changes were needed to accommodate necessary change elsewhere. Such extensive disruption is an almost certain outcome of each subsequent review – so that the continuity of the link between individual MPs and their constituents will be substantially weakened in many places.

Contrary to widespread commentary, the reduction in the size of the Commons isn’t the main cause for this disruption, which is mostly due to the tight limits on constituency size. Simulations of how the aborted 2013 Review might have turned out had the range of permissible electorate sizes been widened suggest that (even with a 600 MP Commons) disruption would have been reduced considerably had electorates been allowed to vary by at least 8% on either side of the average, rather than the mandated ±5%.

But the proposal to reduce the Commons to 600 MPs does have a potential consequence, especially (as at present) when a Conservative government has no overall majority. MPs cannot change the Boundary Commissions’ proposals for the new seats but they do vote on the adoption or rejection of the entire package. Opposition (especially Labour) MPs have few incentives to support the Review. But while Conservative MPs have a collective incentive to vote through the Review (their party stands to gain, for entirely fair reasons), many will fear for their individual positions, either because their seat will disappear, or because they fear competition for the party nomination in a heavily revised version of their current constituency; they might consider voting against the package to save their own seats and with the government’s authority considerably reduced after the 2017 election, there are few levers the leadership can use to persuade them to stay on side. It is by no means a foregone conclusion that the government will get parliamentary approval for the new boundaries.

Should the Boundary Commissions’ recommendations be rejected by parliament in autumn 2018 the next General Election will almost certainly have to be fought in the existing constituencies, which are based on the 2000 electorate (data for which were available when the Commissions began drawing up the current seats): in effect, the UK’s constituencies will be over twenty years out of date.

Which brings us to the PACAC report and to Afzal Khan MP’s private member’s bill. Both, in different ways, address some of the issues raised by the Constituencies Act. Both seem to have run into the parliamentary sand.

PACAC focused on procedural issues raised by the possibility that MPs might reject the final recommendations when they are tabled in late 2018. It noted that under the current rules a further Review could not be completed in time for the 2022 election. Section 3(2) of the Parliamentary Constituencies Act 1986, as revised by the Electoral Registration and Administration Act 2013, requires that the Boundary Commissions must submit new recommendations in every fifth year after a completed Review. Existing legislation, therefore, would mean that the next review after 2018 could not report until 2023.

As PACAC pointed out, only two options would then be left. Either the existing (and increasingly elderly) constituency map could be used once more, with all the adverse consequences that would entail. Or the legislation could be amended to allow a further Review to be completed before May 2022 (a prospect not likely to enthuse the Boundary Commissions, who would by then have conducted two lost Reviews in short order).

Any revisions to the legislation would also have to alter the timetable. A Review currently takes almost three years, with the Commissions developing their initial proposals, conducting mandatory public consultations, and then producing revised and, after further consultation, final recommendations. Once its proposals are enacted by parliament, electoral administrators and the parties have to make arrangements for the next election in the new seats. If that period is set at 18 months (as implied when the Constituencies Act is combined with the Fixed-terms Parliament Act), then even by early 2018, when PACAC deliberated, there would be little or no time to complete a new Review before a 2022 contest. Something, they argued, had to give in the timetable. Their solution: either shorten the time between adoption of new boundaries and the next election (undesirable, they felt, because of the potential for serious administrative mistakes) or curtail the opportunities for public consultation (so shortening the time period required for a Review). Analysis of the public consultation process – which the Conservatives proposed abolishing in 2011 but  was reinstated at the Lords’ insistence – during the 2013 Review shows the minor extent to which the public (as opposed to the political parties and their members) was meaningfully involved. PACAC called, therefore, for the government to debate these alternatives in good time, just in case.

The government responded to the PACAC report three months later, on 11 May 2018. Its position was simply stated: thanks, but no thanks. The current Review, they argued, was too far advanced to do anything more at this stage – and in any case the government was committed to fewer MPs and equal-sized constituencies.

Afzal Khan’s private member’s bill is thus the last means standing of revising the 2011 Act. It retains core aspects of the 2011 legislation: notably the priority of equalising electorates. But it differs in important details. To reduce the potential for very substantial and frequent disruption to the constituency map, it increases the allowed range for electorates from ±5% to ±7.5% (our research suggests that will help) and the period between Reviews from 5 to 10 years (allowing for at least two elections at a time in unchanged constituencies); it also sets the number of MPs at the current level of 650, not 600. And it stipulates that the electorate data should be those for the most recent General Election, rather than (as in the 2011 Act) the electorate in place at the time a Review begins. If the bill were enacted and replaced the Constituencies Act a new Review would be initiated based on the 2017 electorate rather than that in place on 1 December 2015 (and hence, the bill’s supporters argue, would incorporate the growth in registration during the 2016 EU Referendum and 2017 General Election campaigns – and hence more accurately representing the current electorate).

As private members’ bills have less parliamentary time allocated to them than government bills, Khan’s proposal faces an uphill struggle to become legislation and its passage is now doubly difficult. Introduced in July 2017, the bill moved through first and second Readings to its House of Commons committee stage where it is liable to remain, in limbo, as the government has not approved a money resolution needed if it is to progress. This procedural measure is clearly being employed by the government to thwart the bill’s passage – the bill will probably not progress further.

The 2011 Act therefore remains in place, and the focus shifts to whether MPs will approve the Commissions’ recommendations. Initially, the government’s position looked precarious. In addition to the risk of backbench Conservative rebellions, it faced a threat from its DUP partners, who were deeply unhappy with the electoral implications of the Northern Ireland Boundary Commission’s initial recommendations, which appeared to give Sinn Féin a majority of the new 18 seats. Were the DUP to vote with all of the opposition parties against the new seats, the government would be unable to command a majority on the matter, and the Review would fall. But the Northern Ireland Commission’s revised proposals, published in January 2018, seemed more favourable for the DUP, which has apparently changed its position and is likely to support adoption of the new constituencies. This is an important fillip to the Conservative government, as a further election in the old constituencies would have made it harder for them, and easier for Labour.

So is the debate over Britain’s new constituency map now all but over? Probably – but not definitely. The focus now shifts to potential losers from the Review on the Conservative benches. When faced with endorsing or rejecting the Review this autumn, will they put party ahead of personal interests and vote for reform? Or will enough rebel to scupper the Boundary Review for the second time in just a few years? Watch this space…

About  the authors

Charles Pattie is Professor of Geography at the University of Sheffield, specialising in electoral geography.

Ron Johnston is Professor of Geography at the University of Bristol whose work has focused on political geography (especially electoral studies), urban geography, and the history of human geography.

David Rossiter is a retired Research Fellow who formerly worked at the Universities of Bristol, Leeds, Oxford and Sheffield.