Modelled under the voting system used in the European Parliament election (d’Hondt list PR), the new total sees the Conservatives take 45.6% of seats, far closer to their 43.6% vote share and down 12 points from the seats they received under First Past the Post.
The SNP – who will also be over-represented in the next Parliament because of the current voting system – could see their seat share move to 4.4% of seats under d’Hondt, closer to their actual 3.9% vote share. (The SNP back a move a more proportional voting system).
Other parties would have benefited from a fairer system – Labour gaining 14 seats, the Lib Dems 59, the Brexit Party 10 and the Greens 11.
In Northern Ireland, the DUP (-3) and Sinn Fein (-2) would both leave seats with the SDLP (+1) and Alliance (+2) parties both making gains.
The ERS support a move to the multi-member, ranked-choice system of the Single Transferable Vote, used for local elections in Scotland and Northern Ireland.
Darren Hughes, Chief Executive of the Electoral Reform Society, said:
“No government should be able to win a big majority on a minority of the vote. Westminster’s voting system is warping our politics beyond recognition and we’re all paying the price. Under proportional voting systems, seats would more closely match votes, and we could end the scourge of millions feeling unrepresented and ignored.
“Parties like the Greens and Brexit Party won huge numbers of votes and almost no representation. The Lib Dems saw a surge in votes and their number of seats fall. Something is very clearly wrong.
“Voters in Scotland, Wales and Northern Ireland are used to using more democratic voting systems – and having a more cooperative politics as a result.
“Westminster’s system is built on confrontation and warped results, but we can do better than this. We can move to a fairer system, restoring trust in politics and building a better democracy at the same time.”
Researchers have modelled the General Election result under a form of proportional representation.