Sorry, Nigel, but I did warn you. In February, as the pivotal Gorton and Denton by-election was entering its final days, Reform’s leader abandoned the campaign trail in Greater Manchester to attend a book launch at the luxury Raffles hotel in London’s Whitehall.

The title of the newly released tome was How To Launder Money, by convicted fraudster George Cottrell.

But Cottrell – known within Westminster circles as ‘Posh George’ – was not just another former felon turned wordsmith. He is inexplicably one of Farage’s closest confidants. So close, he reportedly refers to Farage as ‘Daddy’.

At the time I wrote: ‘It may seem Reform’s leader has been rewriting the political rules, but it’s a misconception. The rules are actually written by the voters.

‘And up until now they’ve been prepared to overlook – even embrace – his inconsistencies and eccentricities. But, by openly flaunting his relationship with a convicted fraudster, he is at best taking working people in constituencies such as Gorton and Denton for granted. And at worst he is taking them for fools.’

So it proved. Reform were comfortably beaten by the Greens in the by-election.

And over the weekend Farage’s bizarre friendship with Posh George has exploded into a full-blown political scandal following an investigation by The Sunday Times.

In the run-up to the 2024 General Election, Cottrell reportedly provided Reform’s leader with security, staff and the use of a five-storey house close to Buckingham Palace, it disclosed. None of these donations was reported in the register of members’ interests, in an echo of Farage’s failure to report a £5million donation from Thai crypto-billionaire Christopher Harborne.

Reform’s response has been to attack the investigation as a ‘baseless and contrived story, covering a period of time when Nigel Farage was not even an active politician, let alone an elected one’. But the matter is now being examined, along with the Harborne donation, by Parliament’s standards watchdog. And it is not going to go away. Farage and his allies can lash out as much as they like at what they claim are establishment attempts to undermine him.

But the reality is that Reform’s leader is now caught within a labyrinth of sleaze and intrigue similar to the one that fatally ensnared Keir Starmer following his appointment of Peter Mandelson. There are too many strands to the saga for Farage to compartmentalise the issue and draw a line under it.

First there is Posh George himself. Painted as a shadowy figure lurking in the darker recesses of British politics, he is in fact a familiar and gregarious face on the Westminster scene. He enjoys the company of journalists as much as politicians, and is often to be found holding court at a table in the exclusive 5 Hertford Street club in Mayfair.

He is also, as his 2016 conviction for wire fraud demonstrates, as bent as a nine-bob note. In 2014, he offered anonymous drug dealers in the US help in laundering the proceeds of crime into Bitcoin – only to be arrested two years later while travelling through the States with Nigel Farage when it emerged the ‘drug dealers’ were in fact undercover federal agents.

While there is of course no suggestion Reform’s leader was aware of any of Cottrell’s illegal activity, he knew the whole tawdry tale when he turned up to his book launch. And when he accepted his financial help and gifts in kind.

So Farage will be unable to dismiss Cottrell as some carpetbagging minor acquaintance. As one Reform insider told me: ‘George looks at Nigel as a father figure, and Nigel reciprocates.’

Nor will this be the end of the revelations over Farage’s links with shady individuals.

Last weekend he was in the US celebrating the country’s 250th birthday with representatives of President Donald Trump’s MAGA movement. Before the Iran war he was spending an increasing amount of time in Dubai. He has also recently been hovering in Montenegro, where Posh George is based.

And each time he travels he ingratiates himself with another group of high-flying financiers in the banking and crypto world. The majority of them will be fine, upstanding citizens. Some will be a little bit dubious. And a handful, like Cottrell, will have drifted on to the wrong side of the law.

In the past, Farage was able to fend off questions about these associations with a joke and a shrug. But now, his force field is down.

It’s not that he himself has done anything unlawful. Or even that he has regularly and persistently broken parliamentary rules. But, as Sir Keir found with his friendship with Lord Alli, the mud quickly began to stick to his Charles Tyrwhitt suits. And when that happened, no amount of dry cleaning was going to erase the stain.

So for the moment, Farage and his allies are doing what they always do, which is to start furiously punching back at anyone and everyone who dares criticise them. But soon they are going to have to step back and recognise the truth.

The political trajectory for Reform under its current leader is now set. Indeed, it’s been set since October. Back then, Reform were on 31 per cent in the polls, 11 points ahead of Labour and 14 ahead of Kemi Badenoch’s Tories. Today they are on 25 per cent, just five points ahead of Labour and six ahead of the Tories.

The ousting of Sir Keir, and arrival of Andy Burnham, will give Labour a further bounce. Mrs Badenoch will slowly but surely continue to transform the surge in her personal ratings into gains for her party. And as the drip, drip, drip of sleaze continues, Nigel Farage will just as slowly but surely become an albatross round Reform’s neck.

There is no way out for him now. He has broken bread with too many George Cottrells. The crypto billionaires. The MAGA social media tycoons. The Dubai money men.

They are his world. Yes, he can still talk the language of the man on the Clapham Omnibus, Clacton High Street and the vape shop and Turkish barber-lined shopping centres of Red Wall Britain. But they are not Nigel Farage’s priority any more. And they know it.

In Sunderland in the local elections – which were perceived to be a triumph for Reform – I heard the same message: ‘I’ll vote for him this time to get rid of Starmer. But he’s basically the same as the rest of them now. He’s just in it for himself.’

Nigel Farage is. And to his credit, he admits as much. His response to questions about the Harborne cash was to say: ‘It’s not the public’s business.’ The £5million, he boasted, was ‘an unconditional gift... I can spend it on Ferraris if I want’.

He can, and the way he has transformed British politics entitles him to an enjoyable, Ferrari-fuelled retirement. But make no mistake, that retirement is coming.

Nigel Farage can step back voluntarily, or he can continue to see his personal and party poll ratings eroded by revelation after revelation over another rich benefactor. Either way, the end is now in sight.

Over the weekend I spoke to a senior Reform source who said ‘the problem is that I can’t see a future for Reform without Nigel Farage’.

Well, his party is going to have to, because ‘Daddy’ is not going to be around for ever.