I cannot help but notice throughout this thread that a number of posters are suggesting that the electoral system is "broken", and needs changing. It's possible that this cry will be taken up more generally, although I don't think there will be many clamouring for it from within the House of Commons.
The last time this happened was I think after the 1974 election, when the Liberals under Jeremy Thorpe polled nearly 20 percent of the vote but only ended up with 14 MPs. This caused a hell of a fuss, and meant that changing the system entered the Liberal manifesto, where it remains, AFAIK. We now have yesterday's result, which inolves one party polling 13 percent of the vote with 1 MP, and another polling 3.8 percent of the vote, also with 1 MP.
I think it was Churchill who said that FPTP was the worst possible system, apart from all the others. It certainly has failings, but these are mitigated where there are relatively few parties (ideally, less than three). With more parties gaining popular traction in spite of the system, the failings become less tolerable.
Everyone with an opinion assumes that PR is the answer. But here in the UK, we like having MPs with a constituency link, and this makes any form of PR unnacceptable, not to mention over-complicated, and ultimately undemocratic, as the machinations required to form a government, far from enhancing representation, invariably amount to a conspiracy against the electorate.
I therefore think we should adopt the Henderson method.