Once again 10pm was the moment of truth. Not since the national exit poll dropped on election night in 2017, showing the Tories losing their majority, has one poll had such an impact on Britain’s political parties. When YouGov published its election model on Wednesday evening, using the methodology that predicted a hung parliament two years ago, it managed to instil panic, for different reasons, in all three main parties in England — two of which hoped it was wrong while the third feared it would be.

The survey predicted a Conservative majority of 68, with Labour haemorrhaging 52 seats and the Lib Dems marooned on 13, one up from 2017 but seven fewer than it has now, its numbers boosted by defections.

It led