Dan Jukes, an aide to the Reform leader, and the party’s head of policy, James Orr, have both stood down after Channel 4 broadcast the investigation, carried out by a group called Verbatim Investigations, founded by journalists from the Centre of Climate Reporting. Jukes was also shown suggesting what the Channel 4 film described as an illegal way for a foreign donor to give £500,000 through his UK-based son. The proposed £500,000 donation was never made.

The party has immediately started an investigation, and Nigel Farage has insisted Reform “has broken no laws”. He also called it a “clear case of entrapment, and they worked at it for a very, very long time, and they got a couple of our contractors to say things that perhaps should not have been said”.

It must be a bit of a shock to Jukes and Orr to be described as “contractors” in an attempt by Farage – who also appears in the footage meeting the fake US businessman to discuss his planned donation – to distance himself from the whole thing.

Lee Anderson, Reform’s chairman, said this morning that the pair “are not coming back,” even though the party has only just started its investigation into the allegations. Both responses show how damaging Reform figures fear this story could be.

It is not just that the sting operation distracts from the key messages Farage was hoping to land at the conference today. That in itself is a pain, and the kind of thing that all political parties fear when they are embarking on their autumn conferences, which are usually the best opportunity to get uninterrupted news coverage that they’ll have all year.

It is also that the footage puts Reform in the same camp as the run-of-the-mill politicians that it rails against. Farage’s suggestion that MPs should sit in the House of Commons seven days a week was supposed to be part of that campaign to clear politics up. But what annoys voters far more than whether MPs are on the green benches all the time or not is the sense that those politicians are involved in something grubby. This looks grubby.

Reform has also called the whole sting a “hoax”. It’s obviously driven by people who want to expose Farage – but these stings are common in politics. Most MPs and peers are conscious that the people they are meeting for the first time might turn out to have a hidden camera on them – and everyone has agency over the things they choose to say, which is why many attempted stings never make it to broadcast, because the politician deftly avoids saying the wrong thing.

Anyone who watches this footage will have a visceral reaction to the kind of Westminster it represents: knowing smiles between men as they discuss huge sums of money over oysters. It’s a stereotype that politicians try to put a lot of effort into trying to smash, but unfortunately stereotypes tend to exist for a reason. And voters already hold that stereotype about politics. The risk for Reform is that they now lump the party in with all others who they think are also “at it” in some way.

Worse for Reform, it looks as though the party, which trades on its patriotism, is in fact unpatriotic about British democracy: Farage meets an actor posing as a Wyoming-based businessman who wants to donate hundreds of thousands of pounds to the party through his UK-based son – and thanks both of them for their help.

The son says: “I’ll be the registered donor. But then dad will send the money to me and then as soon as that’s done, and all those conversations are had, the money is available.” The reason they are doing this is that the electoral law states that to be a permissible donor to a UK party, someone must be a UK registered voter, or a company registered in the UK. In this case, the son was presented as a permissible donor, but his father was not – even though the conversation makes clear that it is his money that would be coming to Reform through his son.

Instead of worrying about foreign interference in democracy, Farage replies: “Thank you. Well, both of you. Thank you.” He will wish he’d never sat down for shellfish with the pair: that lunch won’t have fatally poisoned his party, but it’s going to weaken it at a time when it is already not in the most robust of health.