There was an unmistakable frisson at the Carlton Club, the inner sanctum of the Conservative Party, last week. Everywhere I turned, MPs and peers were discussing Robert Jenrick‘s imminent defection to Reform.

At that evening reception on January 8, attended by former prime minister Baroness May, Liam Fox, a former defence secretary who twice ran for the Tory leadership, as well as a clutch of shadow ministers and senior peers, the rumour was that the deal was already done.

‘He is going to be Reform UK’s first shadow chancellor,’ one Tory grandee told me. ‘His people can’t stop boasting about it. Who knows if it’s true?’ True to form, Jenrick’s team denied everything.

While Kemi Badenoch herself was not at the packed party, she had spies in the room. I’m told the telephone lines were red-hot to Tory HQ after the event.

A senior party figure told me yesterday – following Jenrick’s shock sacking by Badenoch and subsequent defection to Reform: ‘What you heard at the Carlton Club confirmed the rumours we have been hearing about Jenrick for weeks. He was going to defect because he could not see any other way he could hold his seat.

‘He was going to spring a big surprise in a Sunday TV interview or newspaper. He thought it would give him the leverage to get the biggest job after Farage’s: shadow chancellor. But Kemi’s burst his bubble and wrecked his plans.’

Indeed, I can reveal Jenrick, 44, was slated to appear on Laura Kuenssberg’s BBC Breakfast show on Sunday.

Only hours before that Carlton Club reception, the whole shadow cabinet had attended an ‘away day’, led by Badenoch, at a swish suite of offices overlooking the Tower of London. According to those in the room, Jenrick asked plenty of questions. However, some of his colleagues observed that he uncharacteristically took far more notes than anyone else.

They must be asking themselves now whether he was then already working for his new master. The shadow cabinet ministers then went for a group dinner and Jenrick was reportedly on ‘good form’. ‘He must have felt like Judas at the Last Supper,’ one senior party figure told me last night.

In the days that followed, Badenoch’s office was on strict ‘Jenrick resignation watch’. They did not have to wait long.

Just six days later, after Prime Minister’s Questions on Wednesday, she was handed an explosive document by a disgruntled Jenrick aide. It was his defection speech. And it was nuclear – designed to cause maximum damage to the Tory party.

Not only through its many references to forthcoming local elections in May, which he predicted would be disastrous for the Tories but, in the leaked speech, he was scathing about three colleagues: Sir Mel Stride, the shadow chancellor, Chris Philp, shadow home secretary, and the shadow foreign secretary Dame Priti Patel.

Jenrick, who was enraged when he was not made shadow chancellor after Badenoch beat him to the leadership in November 2024, mocked their lack of media profile in Opposition. He also savaged their record in government.

Having read it through, Badenoch, cool and calm by all accounts, talked to her closest advisers who all agreed he had to go. She slept on her decision and yesterday morning confirmed he was out.

The news was delivered to the public in almost Trumpian style: a pre-recorded video shot at her Essex home which was released on social media just after 11am – timed perfectly to coincide with a press conference Farage was hosting in Scotland.

Badenoch left the job of personally informing Jenrick of his sacking to chief whip Dame Rebecca Harris, who is hardly a political heavyweight – a deliberate slight to her old leadership rival, who would have expected someone rather more senior on the phone.

Though the news came as a shock to many in Westminster, many Tories already knew that Jenrick was in talks with Farage, which culminated in dinner at the private members’ club 5 Hertford Street before Christmas.

This was common knowledge in leaky Reform UK, which used to pride itself on being a tightly run ship. Reform’s newly unveiled London mayoral candidate Laila Cunningham warned only last weekend that Jenrick would not be welcome in the party because he ‘allowed migrant hotels to flourish’ when he was immigration minister in Rishi Sunak’s government.

In Reform’s offices at the Millbank Tower in Westminster, once the home to Tony Blair in his pomp in the 1990s, many shared Cunningham’s view. ‘Even at that point Nigel had not made his mind up about whether to take Jenrick,’ one well-placed Reform figure told me. ‘He’s worried that too many former Tories will, to coin a phrase, spoil the broth.’

Indeed, last summer, when Jenrick attacked Labour after an asylum seeker living at a migrant hotel in Epping assaulted a 14-year-old girl, one of his loudest critics was Farage – who accused Jenrick of hypocrisy due to his own record on immigration.

At the time the Reform leader said: ‘Jenrick is a fraud, I’ve always thought so.’

Only six weeks ago, Jenrick was spotted enjoying lunch with his former Tory boss David Cameron and the latter’s right hand man George Osborne in Oswald’s, the sister club of 5 Hertford Street. So when did Jenrick make his decision – and why?

The answer lies in Badenoch’s dramatically improved performance as PM since the Tory conference in Manchester in October and her rising poll ratings. Jenrick, once a ubiquitous presence on social media and the airwaves (he often irritated his shadow cabinet colleagues by straying into their policy areas), has been markedly more restrained of late.

Even his backers fell silent as pro-Jenrick WhatsApp groups ceased their chatter as Badenoch’s ratings ticked upwards.

Now he’s crossed the floor, it’s clear Jenrick isn’t in the prime position he was aiming for.

I’m also told Reform HQ was furious that Jenrick’s speech had been so foolishly leaked to Badenoch’s office.

Jenrick is keen to remind his detractors in Reform that he resigned from government in December 2023 over its failure to control Britain’s borders.

But many will remember that oh-so principled stance came a mere three weeks after Rishi Sunak passed him over for Home Secretary, which Jenrick had assumed was his for the taking.

Jenrick’s aides then crudely revealed they had a ‘grid of s***’ on Sunak – a series of explosive interventions designed to further destabilise the then beleagured prime minister – which confirmed the view of many of Jenrick’s colleagues that he was both treacherous and unreliable, a reputation he has only enhanced this week.

Not that any of this will stop the fiercely ambitious Jenrick seeking high office. His lofty aspirations are shared too by his American lawyer wife Michal Berkner, 52.

Many will recall her look of horror when it was announced Badenoch had won the leadership in 2024 and her flamboyant eye-rolling when the applause for Badenoch lasted longer than she wished.

It’s thought that Berkner was the force behind the rebrand in his appearance, persuading him to take the fat jab Ozempic – thanks to which he has lost 4st.

A senior Tory, delighted to have wrecked his plans to announce his own defection, told me last night: ‘Kemi went out of her way to make it work for Robert in the shadow cabinet but he was sniping and scheming at every turn.

‘He’s now really entered the lion’s den. I think he will find the sniping and scheming has already started at Reform. About him.’