As things stand, when Britain goes to the polls in less than four weeks the Conservatives are set to lose somewhere between 7mn and 9mn of the 14mn votes they secured in 2019. The final result is likely to be the party’s lowest ever share of both votes and seats.

This outcome would have been completely unthinkable five years ago, when Boris Johnson delivered the Tories’ largest majority in 30 years. But should it have been?

It is notable that support for the Tories since 2010 was generally sustained or rising for the first nine years — despite austerity and enduring economic stagnation — before turning sharply in early 2020 and marching steadily downwards. The pandemic lockdowns, the “vaccine bounce” in the polls, the partygate scandal, even Liz Truss’s infamous “mini” Budget: all are mere blips on a clear linear trend.