Let’s suppose the opinion polls are right. If they are, we are headed, not just for an extraordinary European election this week, but for the biggest revolution in our political system since the universal franchise. And revolutions, I’m afraid, rarely end well.

The most detailed survey of opinion, a YouGov mega-poll with more than 7,000 respondents, has the Conservatives in fifth place behind the Brexit Party, Labour, the Lib Dems and the Greens. I know that it’s conventional, in the run-up to polling day, to talk up your chances, but I see no point in insulting people’s intelligence. My party is heading, not just for defeat, but for annihilation.

To see the scale of the catastrophe, look at what have until now been considered the Conservative Party’s worst results. The general election defeats of 1906, 1945 and 1997 are often cited as historic lows. The Tory share of the vote in those elections was, respectively, 43 per cent, 36 per cent and 30 per cent. In the 2014 European elections, it sank to 27 per cent. In the 1995 local elections, at the height of John Major’s unpopularity, to 25 per cent – its nadir to date. But on Thursday, if YouGov is right, it will plummet to 9 per cent. Yes, you read that correctly – 9 per cent.

The idea that a party can pick itself up after a result like that and win a general election is for the birds. Campaigning in my Home Counties region, I keep being told by Tory-minded voters that this poll doesn’t count – that it’s only a European election, that it shouldn’t be happening at all, and that it’s therefore an ideal moment to give the Conservatives a bit of a slap. But 9 per cent is not a slap; it’s a knockout blow. And, in our political system, when one of the two main parties is stretched out cold on the canvass, the other wins the bout.