Of the 25 seats that the Conservatives have lost in byelections to the Liberal Democrats and their predecessor parties, only one produced a bigger swing than North Shropshire. What happened then should discomfort today’s Liberal Democrats locally – and the Tories nationally. In 1993, the Lib Dems captured Christchurch on a 35% swing. Diana Maddock won with a majority of 16,427. At the following general election, the Conservatives recaptured Christchurch – but crashed to their heaviest national defeat in living memory. The Tories have recovered nationally from other byelection losses, notably when Margaret Thatcher was prime minister; but their support never slumped as much in those midterm byelections. The swing in North Shropshire was almost as high as in Christchurch: 34%. The Tories might well recover the seat next time; but will they recover enough across the country?
As those financial advertisements remind us, the past provides no guarantee of future performance. But there are good reasons for Boris Johnson to feel exceedingly nervous this weekend. His main – some would say only – claim to the loyalty of his party is that he is a vote winner: for his candidate to crash to such a massive defeat raises obvious question about his electoral appeal. Polls provide supporting evidence. Ipsos Mori has been measuring prime ministers’ satisfaction ratings for more than 40 years. Johnson’s current rating is not the worst, but it is heading in the wrong direction. His latest figures are: satisfied 28%, dissatisfied 65% – a net score of -37, compared with +3 in the wake of his 2019 election victory. A separate YouGov survey finds that 57% regard Johnson as incompetent. Only 31% say the same of Keir Starmer. To add to Tory woes, this month’s two byelections show clear signs that tactical voting is making a comeback. Two weeks ago in Old Bexley and Sidcup, where the Lib Dems stood no chance of coming close, let alone winning, Labour’s share was up and the Lib Dem share down. This week in North Shropshire, those trends were reversed. Byelection campaigns develop their own momentum: tactical voting in general elections is never as great. But back in 1997, when Tony Blair and Paddy Ashdown led their respective parties, tactical shifts of just a few percentage points cost the Conservatives about 30 seats they would otherwise have held. Nothing like that happened in 2019. Lib Dems could not bear the thought of helping Jeremy Corbyn – indeed some Lib Dem candidates report losing supporters to the Conservatives, to be sure of keeping Corbyn out of Downing Street. Jo Swinson, the then Lib Dem leader, was not actively disliked by Labour supporters but neither did she have the positive appeal of Ashdown two decades earlier. Today, with Starmer and Ed Davey at the helms of their parties, tactical voting seems to be enjoying a revival. Suppose it has the same impact at the next election as in 1997. The Tories would have lost heavily then, even without tactical voting. Next time it could make the difference between the Conservatives having enough MPs to continue in office, or Johnson being replaced by Starmer, at the head of a minority Labour administration. Given the size of the mountain Labour must climb to achieve an overall majority – a lead of about 12% in the popular vote – a minority government may be the best real hope for Labour and the biggest threat to the Tories. Which gives us the paradox that the slump in Labour’s vote in North Shropshire should cheer Starmer and terrify Johnson. Peter Kellner is a political analyst and former president of YouGov