Changing the Commons: How many MPs? How equal their electorates? Part 2

Yesterday, in part one of this blog, Ron Johnston, David Rossiter and Charles Pattie outlined the challenges that are likely to make the 2016 boundary review as (if not more) disruptive than the aborted 2012 review. Here the authors consider how issues around the accuracy and completeness of the electoral rolls will impact the review process and make the case for amending the Bill in line with PCRC recommendations made in March.

Can any of the potential disruption of the 2016 boundary review be avoided? Is it possible to maintain the general principle of greater equality of constituency electorates but modify the rules and Boundary Commission practices, so that a new constituency map can be created that differs less from the current one than in the 2012 recommendations? In research that we did in 2014, published by the McDougall Trust, we showed that there would probably be much less disruption if: (1) the tolerance was increased from +/-5% to at least +/-8%; and (2) the Boundary Commissions, especially the Boundary Commission for England, were more prepared to split wards when creating constituencies.

That research also showed that the reduction in the number of MPs from 650 to 600 did not exacerbate the disruption. Even if the number had been retained at 650, substantial changes would have been needed across the four countries within the UK, and then within them, because of the adoption of a single quota and the +/-5% tolerance.

Screen Shot 2015-07-14 at 16.55.26

The table illustrates this, comparing the current allocation of 650 seats to that which would result from use of the 2014 and 2015 (general election) electorates. Wales would lose eight seats and, with an electoral quota of either 69,909 (2014) or 71,381 (2015) and a +/-5% tolerance, undoubtedly need its entire constituency map redrawn. Scotland and Northern Ireland could also lose seats, whereas England would gain an extra 6-8. A new map, even with 650 MPs retained, will be very different in much of the UK from the current one. (The quota, using the 2014 electorate figures, would be 69,909, and all constituencies would have to have electorates between 66,414 and 73,401. In Northern Ireland, seven of the current 18 constituencies had electorates then with fewer than 66,414 voters and four had more than 73,401. Even though the seven others were within the tolerance, it is almost certain that all 18 would have to be changed to meet the requirements).

There is, however, a major unresolved issue regarding the accuracy and completeness of the electoral rolls that could have a substantial impact on the number of registered electors in December 2015, and hence the determination of the electoral quota and the allocation of seats when the Boundary Commissions start work in March 2015. We are currently in a transition period in the switchover to Individual Electoral Registration, which is due to end by December 2016 but could – if the government so determines between June and August 2015 inclusive – be ended in December 2015. The crux of the issue is the number of people currently on the electoral roll but who have not registered individually. The Electoral Commission’s recently-published report Assessment of progress with the transition to Individual Electoral Registration estimates that the number is c.1.9million, and if the transition is ended this year, then they will all be removed from the electoral rolls assembled at the end of the year (unless they re-register in the short remaining period).

The Electoral Commission has recommended that the transition period continue into 2016. If the government does decide to end the transition period early, however, then the number of registered electors used in the Boundary Commissions’ exercise starting in March 2016 could be more than 1.5million fewer, with very clear implications for the outcome of that exercise at all scales: the determination of the electoral quota; the allocation of constituencies across the four countries and the nine regions within England; and the detailed boundaries of most of the individual constituencies. The number of constituencies allocated to London could vary by as many as five depending on whether the 1.9million are removed from the roll and, in general, urban areas would be under-represented with a reduced electorate.

This would be undesirable. Analyses of the revised proposals in the review aborted in 2013 indicates that in the reduction of seats from 650 to 600 Labour would have lost 35 MPs if the 2010 election had been fought in the new constituencies and the Conservatives only four. The collapse of the Liberal Democrats in 2015 and the rise of the SNP would change that slightly, but there is no doubt that the Conservatives would be the main beneficiaries of a review starting in 2016 with only 600 seats to be determined. If the transition to IER were to be ended this year, the Conservative gain would undoubtedly be greater, because the English shires would gain seats relative to the UK’s large cities.


Apart from that crucial issue regarding the electoral register, can anything be done to modify what the Boundary Commissions do? Can the rules be changed before they start work in February 2016?

In March 2015 the House of Commons Political and Constitutional Reform Committee published a report What next on the redrawing of parliamentary constituency boundaries?, having taken evidence from a range of interested parties, including the secretariats of the four Boundary Commissions. It made two firm, unanimous, recommendations: that the tolerance be changed from +/-5% to +/-10%; and that the number of MPs not be reduced to 600. The government did not respond formally before Parliament was prorogued, but the evidence given to the Committee by the then Minister – Sam Gyimah – and the statement in the Conservative 2015 election manifesto indicate that the Conservative party, and hence the current government, is unlikely to agree to any change, or to facilitate the passage of an amending Bill through Parliament during the next six months, unless they are under considerable pressure to do so. David Cameron clarified that position on 1 July at Prime Minister’s Questions saying that we should get on and create more equal constituencies and reduce the number of MPs to reduce the cost of politics. The need for pressure is thus even greater.

Where might that pressure come from? Individual members (who, as the report in the Independent on July 10 indicated, are concerned) could press the case on the newly-constituted Public Administration and Constitutional Affairs Committee, which includes constitutional matters in its remit. It could undertake a quick review of the evidence and reiterate its predecessor committee’s recommendations, which might stimulate a response, perhaps through the Backbench Business Committee. Any change it proposed would almost certainly be supported by Labour and the Liberal Democrats (the latter are important in the Lords) and probably by a number of Conservatives concerned about the potential disruption – what new MPs wants to see their constituencies disappear within 2-3 years of being elected?!

The case for the relaxed tolerance is that it will reduce disruption and allow the Boundary Commissions to recommend new constituencies that differ less from their predecessors, which are more likely to fit within the local government map, and which will be more in line with communities of interest.

A short amending Bill could ensure that those changes are made, changes that would be widely (if not universally) welcomed. And it could also change two administrative provisions of the 2011 Act which most – including the Boundary Commission secretariats – would welcome.

  • The current Act requires Public Hearings to be held during the 12-week period: it would be much more efficient if they were held immediately after that period (although in the original Bill the government – i.e. the Conservatives – wanted there to be no Public Hearings/Local Inquiries);
  • The current Act indicates that if the Boundary Commissions take ward boundaries into account (as they certainly will do) then they should use those deployed at the latest local government election before a review begins. In some places a new set of wards has been in place for a year or more but has not been used because there has been no local election (in many areas they are held quadrennially only). It would be better if wards in place at the time when a review commences – even if not yet used – were deployed, reducing the potential for confusion at future general and local elections, especially if the two are held on the same date.

Such changes would not be controversial and would make for a more efficient review procedure.


Political parties, nationally and local, and MPs are facing a major disruption to the UK’s map of Parliamentary constituencies over the next three years. Some disruption is desirable – to remove the over-representation of Wales and some other parts of the United Kingdom in the House of Commons and to limit the variation around the average constituency electorate. It should be possible to reduce that disruption while maintaining the general principle of equality of representation – a change that would be widely welcomed within the political community. But is there a political will to make the changes in time?

Unless the next review of constituencies is to be delayed (again) – which would probably mean the 2020 general election being held in the current 650 constituencies which were defined in England using electoral data for the year 2000 – then an amended Act has to pass through all of its Parliamentary stages by February 2016. The timetable thereafter is extremely tight, especially for England, whose Commission is responsible for 85 per cent of the UK’s constituencies. Parliament must act quickly, if it believes that there should be more than 600 MPs and that constituencies should vary a little more in their electorates than the current legislation allows so as better to represent the country’s communities.

Click here to read part one of this two-part blog, which considers the review that was aborted in 2012 and outlines the challenges currently lie ahead for the 2016 review

About the Authors

Ron Johnston is a professor in the School of Geographical Sciences at the University of Bristol; David Rossiter is a retired Research Fellow who formerly worked at the Universities of Bristol, Leeds, Oxford and Sheffield; and Charles Pattie is a professor in the Department of Geography at the University of Sheffield. They have written together on the Boundary Commissions and constituency definition in the UK since the early 1980s and co-authored The Boundary Commissions: Redrawing the UK’s Map of Parliamentary Constituencies (University of Manchester Press, 1999).

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