For a year or more after the 2017 election, your columnist’s most frequently asked question from politicians, journalists and many others, was why the polls have remained so stable, in spite of all the political turbulence. That has completely changed in recent months, with the latest figures showing particularly dramatic moves. So what should we make of them?

Importantly, both main parties have lost support recently. In 2017, the combined vote share of the Conservatives and Labour in Great Britain was 84.5 per cent (remember that polls usually do not include Northern Ireland, so the frequently cited figure of 82 per cent understates the extent of the fragmentation). Even as recently as the start of 2019 this figure was 76 per cent in the polls. But, since then, something dramatic has changed. Two of the three latest polls have shown the major parties’ combined share dropping below 50 per cent.

This is extreme by historical standards – the only precedent came at the height of the SDP search after the Crosby by-election in 1981, when the equivalent number was 46.5 per cent. That aside, there hasn’t been anything comparable to this level of fragmentation in Britain since polling began 80 years ago.