Two quick observations:
a) The swing to the Conservatives was massive, roughly duplicating the Crewe & Nantwich result. It's one thing for third parties to record huge swings in by-elections that are not repeated at General Elections. It's quite another when it's one of the main parties. Labour teeters on the brink of the abyss. The Conservatives look set for a landslide.
b) UKIP's near-12% result in a UK Parliamentary election suggests that it must be approaching a relevance threshold at which Parliamentary seats may come into the equation. Furthermore, it is by no means obvious that UKIP votes should really be understood as Conservative votes by proxy in this context - it's one thing for Conservatives to vote UKIP in European elections; quite another for them to vote UKIP in a by-election when the Conservatives were the natural party to vote for to overthrow the government and, at least as the campaign began, faced a material challenge in achieving the swing they needed. Those 12% look like convicted UKIP voters to me, not Conservative voters wearing temporary anti-EU badges.
