Conservative MPs are worried. They weren’t worried when Andrea Jenkyns, formerly one of their number, defected to Nigel Farage’s Reform UK party. “I thought she already had,” was a common reaction.

They were uneasy when Tim Montgomerie – the founder of the Conservative Home website, the online voice of the Tory grassroots – defected last week. He represents a strand of mainstream opinion in the party, suggesting that many members could follow him.

They were properly spooked, however, by last week’s unsourced report that Elon Musk was considering a $100m donation to Farage – which prompted follow-up stories about how the American billionaire could get around the ban on foreign donations to British parties.

If there was less to that story than met the eye, here comes Nick Candy, the property magnate and husband of Holly Valance. A former Tory donor, he is now planning to donate to Reform, and has been appointed treasurer of the party, in charge of raising more money. He says he intends “to raise enough funds for them to win the next general election”.

I have more faith in British voters than to believe that they can be bought – and I think the fundamentals are still against Farage.

However, it is certainly true that he has an opportunity, which he started to exploit in the election this year. Millions of people voted to leave the EU because they wanted less immigration; the Tories made the leader of the Leave campaign prime minister and he tripled immigration. It has taken a while for the scales to fall from the eyes of many Tory members who supported Boris Johnson, but that dawning of enlightenment is far advanced now.

The biggest drag on Kemi Badenoch at the next election is that she was a member of the Tory government that betrayed its promises on immigration. And Farage’s biggest advantage is that he offers the option of something that looks like an alternative Tory party, that is not tainted by its failures in office.

But that is what he offered in July – and only 14 per cent of voters bought it, electing a mere five MPs. (And despite their small number, they are a fractious bunch: in several votes in the Commons, those five MPs have divided three ways.)

How is Farage going to replace the Tory party and – even more unlikely – become prime minister? One opinion poll so far, four-and-a-half years from the likely date of the next election, has put Reform ahead of Labour. It is quite possible that statistical volatility and anti-politics sentiment will produce a poll in the next few months that shows Reform ahead of both the two main parties.

But that is not enough. History is on Badenoch’s side. Elections are won in the centre ground, and Farage has shut himself off from the broad mass of moderate opinion that he would need to break through. He doesn’t agree with the NHS and he wants to slash public spending. If that isn’t enough to put off the median British voter, he also thinks Donald Trump is great.

To make matters worse, his admiration is not necessarily reciprocated. David Maddox, our political editor, reported some fabulous backbiting yesterday from one source on Trump’s team, who said: “Farage is not that close to Trump.” He was instead described as “an eccentric British fanboy who they indulge, but he hasn’t been of much use and [they] think he just wants to bask in reflected glory”.

Not only is Farage’s view unpopular in Britain, but it seems to be unpopular with some of the people around Trump himself.

All this is true before Farage even gets to the sharp end of building a machine capable of delivering MPs in large enough numbers to overtake the Tories. Before the election in July, Farage had to disown candidate after candidate who turned out to have unsavoury records. He even disowned and sacked the contractors that Reform had hired to vet candidates, saying they hadn’t done the job properly.

And after all that, one of the five Reform candidates who was elected, James McMurdock, the MP for South Basildon and East Thurrock, was accused of misleading voters about the seriousness of his 18-year-old conviction for violence against a former girlfriend.

This has been the story of Farage’s political life. Every party he has led – Ukip, the Brexit Party and Reform UK – has attracted some candidates who cannot be allowed out in public. He has had the most extraordinary run of bad luck – and I don’t think it is coming to an end.

Badenoch needs to stick to the centre-right ground that the Tory party has always occupied. Let Farage struggle in the deeper end of the pool. In the end, his opinions are too far out of line with the moderate centre to succeed.