The Shape of our Democracy
Firstly a note about browsers, the diagrams below work great in Firefox on Ubuntu, with little popup tooltips when you hover over the dots. Google Chrome does not seem to display the tooltips which is a bit of a shame. Internet Explorer probably doesn’t display the diagrams at all, upgrade to Firefox.
There has been much talk of a possible hung parliament, this is what happens when one party does not get enough seats in the House of Commons to survive a vote of no confidence in the government. So the other parties, if they felt like it, could bring down the government at any time. It isn’t ideal, and coalition governments formed by parties doing deals to gang up on the remaining parties tend not to last that long. There are worse things than a hung parliament that can happen with our first past the post voting system, a party could win the most votes nationally, but actually a different party could get more seats, perhaps even enough to win outright without a hung parliament. That is a very very bad situation. Luckily we have a very stable country and the chances of a civil war starting are low, here the leaders are more likely to step outside and settle the matter like men, with a game of rock-paper-scissors. Joking aside, this is a scenario where having a constitutional monarchy with the Queen as commander in chief of the armed forces seems like a rather good idea.
So what does happen in the different possible scenarios? A regular swingometer won’t tell you the full picture so we have put together something rather different. The triangle below plots the outcomes of different predicted results based on different national percentages of the vote. It is based on data from the UK Polling Report swing calculator assuming 10% of the vote is “other” and sharing out the remaining 90% in every possible combination between the three main parties (it actually goes from 1% to 88% for each party because the calculator doesn’t like zero values) so at each corner of the triangle is the maximum landslide for one of the parties. The area in the middle with the darker dots is the hung parliament zone, the dots are coloured according to which is the biggest party, which would be the one trying to form a minority government. At the centre is a white dot marking the 30:30:30 share of the vote point. If this happens the seat distribution is about Labour:300, Conservative:200, Liberal Democrat:100 which shows some of the surprising results that can happen. The green lines divide up the regions according to the party that won the national vote, you can clearly see that the divisions based on seats are not aligned with the national vote lines, it also becomes pretty clear why the Liberal Democrats are not fans of the current voting system.
Methodology and Caveats
- The data assumes “Other” (Independents and small parties such as the Greens and the Pirate Party) win 10% of the national vote, which is a bit high.
- Boundary changes and other issues could well mean we plotted the results of past elections in the wrong place, the seat numbers for the past election are the predicted seat results for this election, not the actuals from the past one.
- Uniform National Swing isn’t the only means of guessing seat results from changes in votes, local issues can change the results in unexpected ways, it is just an approximation
- The data was generated from a series of Python scripts running on Ubuntu Linux, firstly using twill to fill out the form, then beautifulsoup to read the results, finally the output was processed by a script to directly write the SVG files.

