Something extraordinary is happening in British politics right now. I’ve seen nothing like it before and I don’t think that either Labour or the Conservatives quite realise what is about to hit them.

I’m talking about the juggernaut that is The Brexit Party. Having cleaned up in the recent EU elections, it now stands a good chance of winning its first seat in Westminster later this week in the Peterborough by-election.

That was my impression at the weekend, at any rate, after attending a rally, meeting party workers and talking to candidate Mike Greene, party chairman Richard Tice, party co-founder Nigel Farage, and MEP-elect Martin Daubney among others.

Peterborough was, until recently, a Labour seat. But it’s also strongly pro-Brexit. This makes it hard to predict the outcome: will the voters maintain their tribal allegiance to Labour – regardless of the fact that the candidate didn’t turn up to the hustings, preferring to hang out with Gordon Brown – or will they go for the only major party with a clear and unequivocal position on hard Brexit?

Nigel Farage is optimistic but tells me it’s too close to call. And I don’t think this is a case of getting his excuses in early. The momentum is definitely with the Brexit Party. But as Farage explained, Labour knows the names and addresses of every single voter and will be doing its damnedest to mobilise all of them on the day even if it means ferrying them to the polling station in wheelbarrows.

The Brexit Party, on the other hand, was founded less than two months ago — so is largely reliant on the busloads of fired-up volunteers who descended from all over the country at the weekend to help canvas support.

I heard from several Brexit Party workers that most of the Conservative voters they’d spoken to were going to vote Brexit Party instead. This seems terribly unfair on the Conservative candidate Paul Bristow who is a decent chap, a red-blooded Tory and a proper Brexiteer. But this, unfortunately, is the price that Conservative candidates are now paying for a) for the party’s betrayal of Brexit and b) the fact that Conservatives haven’t really achieved a single Conservative thing during their entire ten years in office.

(Perhaps in the comments below you can help me make a list of all the unConservative things the Conservatives have done in the last ten years which make a mockery of Conservatism. I’ll turn this into a separate column).

British politics so badly needed a shakeup. But I still can’t quite believe that it’s actually happening now. That’s the thing about revolutions: you spend years and years thinking that they’re inevitable, amazed that they haven’t happened yet. Then when they come, they’re a massive surprise.