In theory, British by-elections do not justify the attention they receive. Few people vote in the special elections, which are held between general elections to fill a vacant seat in a constituency. By-elections are not always reliable guides to the overall mood of the country. Besides, the Conservative government still has a respectable majority in the House of Commons. When it comes to passing bills, it doesn’t matter greatly if Labour gains a couple of new MPs.

The reason by-elections matter is that they matter to politicians. Despite their vaunted precision, opinion polls can seem not quite real–just numbers in a table. Watching an actual seat change allegiance is a vivid sign of what might happen on an MP’s own turf at the next general election. So the fact that the Labour Party comfortably won two by-elections on February 15th, in seats previously occupied by Conservative MPs, will cause despair in the governing party.

In Kingswood, near Bristol, the Tories picked up 35% of the vote, down from 56% at the last general election in 2019. In Wellingborough, a town in Northamptonshire, the party won just 25% of the vote, down from 62% in 2019. According to Sir John Curtice, a political scientist at the University of Strathclyde whose aptitude for numbers appears unaffected by lack of sleep on election nights, the drop in Wellingborough was the largest that the Conservative Party has suffered in any by-election that it was defending since the second world war.

The by-election in Kingswood was triggered by the resignation of a Conservative MP who objected to the government’s growing enthusiasm for fossil fuels. The one in Wellingborough was caused by the recall of Peter Bone, a Tory MP who was found to have bullied a worker in his office (which he denies). As one Labour MP put it before polling day, voters don’t like it when the incumbent party is responsible for a by-election. They tend to express their annoyance by voting for someone else.

Terrible as they are, these results are even worse for the Tories than they might seem. Labour has recently made by-election upsets seem routine. They are not. Alia Middleton, who studies politics at the University of Surrey, calculates that only 48 seats changed hands at by-elections between 1979 and 2022. In half of those cases, the Liberal Democrats and their predecessor parties, notorious by-election specialists, grabbed the seat. Since October 2023 the Labour Party has now snatched five Conservative seats in a row.

In both seats, Reform UK added to the Conservative Party’s misery. The right-wing party, which stands for tax cuts and much lower immigration, won 13% of the vote in Wellingborough, its best result so far. It even managed to win 10% of the vote in Kingswood, despite much huffing about how the by-election was a waste of money because boundary changes will soon transform the constituency. Reform UK is polling in the low double digits, according to The Economist‘s poll tracker; these results suggest the polls should be taken seriously.

Reform UK poses a danger to the Conservative Party because of the post-Brexit reorganisation of British politics. Following the referendum in 2016, the Tories managed to corral most of the people who voted Leave; by contrast, Remain voters have been divided among Labour, the Liberal Democrats, the Greens and the Scottish National Party. As a result, Tory voters are now fiercely Eurosceptic and opposed to mass immigration, which makes them susceptible to a populist challenger. Ipsos, a pollster, finds that Conservative supporters cite immigration as a major issue more than they cite inflation, the economy, the National Health Service or anything else. To Reform UK, the Conservative Party resembles a whale carcass gently falling to the sea floor–a nourishing meal for a much smaller creature.

In Wellingborough the Tories argued that a vote for Reform UK was in effect a vote for the Labour Party. That line seems not to have worked. In Kingswood the Conservative Party candidate stood as a sturdy defender of the local green belt, arguing that new homes ought to be built in next-door Bristol. That seemed not to work, either. Nothing really is.■