On Monday, attendees of the UK Labour Party conference voted in favour of including a pledge to introduce proportional representation into its manifesto for the next general election. Of course, Proportional Representation can mean many things, so in this series of articles I’ll be looking at the effect of different variations of PR on the UK Parliament.
In my last piece in this series, I’ll be looking at how dividing the UK into regions, and going proportional within these regions, could have an impact on the number of seats in Parliament. Earlier, I looked into setting thresholds to get into Parliament, how seats are allocated, and how to keep a Mixed-Member Proportional system proportional.
For these examples, I’ll be using the results of the 2019 election as the inputs to these calculations, with an acknowledgement that many voters would vote differently under PR than under the current First Past The Post system. I’ll be allocating seats to the nations and regions of the UK according to their mid-2020 population estimates, and I’ll be using the d’Hondt for allocating seats between parties and between regions without any minimum thresholds.
One Nation, One Region
Allocating seats on a nation-wide basis is the purest way to divide seats between parties. It means that every party that gets a certain number of votes will get a seat in Parliament, regardless of how thinly-spread or highly-concentrated their vote share is.
For a 650-seat Parliament, any party that gets around 0.15% of the nation-wide vote, or 50,000 votes, would be able to get a seat in Parliament. That would make it very easy for what would normally be considered to be a fringe voice to make its way into the Commons.
Nations and Regions
When the UK was in the European Union, the UK elected its MEPs not from a single nation-wide constituency, but from constituencies in the representing the nations and regions. Each of Scotland, Wales and Northern Ireland constituted a region, and England was divided into nine regions.
We will allocate the 650 seats of the UK proportionally based on their populations, and then allocate each region’s seats proportionally based on their respective vote shares.
The effective threshold that a party needs to get into Parliament now increases from 0.15% to a little over 1% (based on the largest region). This presents a challenge for parties whose support is spread thinly across the country, as they’re unlikely to reach the effective threshold anywhere. Even smaller nation-wide parties that manage to get there will not do as well, due to the larger step for each seat and missing the effective threshold in each region.
Narrowing Further
Elections for the Scottish and Welsh Parliaments have regions that contain between 11 and 17 seats. To see the impact of this replicated across the UK, we will create electoral regions within each of the principal regions, targeting 10–20 seats each.
Depending on the region, the effective minimum threshold needed to enter Parliament is in the range of 5–10%. I attempted to base regions along county lines, and on these regions, the Green Party only manages to get a single seat in one of the larger regions. Meanwhile, the larger parties, and in particular the Conservatives, would have outperformed their national vote share by enough that they may have been able to form a minority government.
Having smaller regions has the potential to strengthen the connection between MPs and constituents, as each MP will represent a smaller area. However, these smaller regions also have the potential to damage proportionality. As with other things in proportional representation, there is a balance to find between these two goals.
