In the United Kingdom, candidates to the House of Commons are elected in single-member constituencies districts with the first-past-the-post system: an elector can cast one vote for at most one candidate, the winner is the one who has the most votes.
With this system, the last general elections (December 12, 2019) were trumpeted to be a triumph for Boris Johnson because the Conservative Party won a very comfortable majority of seats – 365 out of 650 seats (or 56.2%). But, if a proportional system was used (as in the European Parliament elections, see Table 1), the results and their interpretation change drastically: the Conservative Party, with 43.6% of the votes, would obtain only 284 seats, and the coalition (Labour, the SNP, the LibDem and the Greens) would have won a majority of seats (209+25+75+18=327 out of 650).
Such distortion is not specific to this election. The impressive 61% number of seats of Margaret Thatcher in 1983 was obtained with 42.4% of the votes and when in 2005 Tony Blair's Labour Party won a comfortable majority of 55.1% of the seats, he did it with 35.2% of the votes: only 3% away from the “worst defeat” of Jeremy Corbyn (32.2%). Almost the same results but not the same interpretation.
