A vote for Nigel Farage's lot would put Starmer in No 10, warns Rishi Sunak... but he admits he's 'too busy' to watch the former UKIP leader on I'm A Celeb

Rishi Sunak and Nigel Farage were separated by 9,000 miles, but both of them were talking about immigration.

While the former Ukip leader was in a jungle clearing, trying to debate UK border policy with clueless 'influencer' Nella Rose, the Prime Minister was wielding a lopsided hammer in a Sunderland car plant and digesting the latest eye-watering migration figures.

The announcement that 745,000 more people entered the UK last year than left the country has shaken a Tory party which had allowed itself to feel a glimmer of electoral optimism after Jeremy Hunt's tax-cutting Autumn Statement on Wednesday.

On ITV's I'm a Celebrity, Mr Farage put it starkly to Ms Rose – and the legions of watching voters – by pointing out that the population has increased by ten million since 2000, leading to an inevitable impact on public services.

Canny as ever, Farage then used the camp's Bush Telegraph to declare that he would 'never say never' to becoming Prime Minister.

This is more than minor-celebrity gossip-fodder: Mr Farage is still closely connected with Reform, the successor to his Brexit Party, which is polling as high as 11 per cent. If this percentage share is repeated at a general election it would split the anti-Labour vote and hand a landslide to Sir Keir Starmer.

And it all comes after the veteran anti-Islam populist leader Geert Wilders won a dramatic victory in last week's Dutch general election,

Speaking to the Mail on Sunday, Mr Sunak – who makes clear that he is too busy to actually watch Mr Farage on the programme – said: 'A vote for everyone who is not a Conservate is a vote to put Keir Starmer into office.

'The question for people who care about tackling migration, who want to get our taxes down, who think we need to have more common sense in our discourse is: do you want Keir Starmer or me to be your Prime Minister?'

Mr Sunak asked voters to be patient, pledging that he is committed to delivering more sustainable levels of migration.

He said: 'There is obviously a lot more to do and that's why we need to take action. I announced previously significant tightening up on the number of dependants that students can bring, which has seen a very striking rise over the past year or two.

'This represents the single biggest measure of restriction on legal migration that anyone's announced in years. That should give people a sense of my determination to bring these numbers down.

'As we go over them, as we see other areas of abuse, we won't hesitate to take action and clamp down.' Despite reports of Cabinet splits over his efforts to use new legislation to save his deal to send illegal migrants to Rwanda, the Prime Minister said it should be remembered that there has been a fall in the number of small boats migrants arriving across the Channel. 

He said: 'I've come into this job, I've had it for a year and I've already got the numbers down by a third, so I think people can trust me when I say I'm going to do something, I'm going to deliver on it.

'I need to finish the job and that means getting the Rwanda deal up and running. I'm prepared to do whatever is necessary to get that scheme operational.'

Speaking at Nissan's plant in the North East – chosen to trumpet a new £2 billion investment in electric car technology – Mr Sunak spoke of his hope that his changes will finally place the country on the path to becoming 'Singapore-on-Thames', the vision of a post-Brexit Britain boasting a low-tax, low-regulation regime which is attractive to investors.

He said: 'We are signing trade deals, that's a big advantage of Brexit. We are one of the fastest growing nations in the world. We've cut red tape for small businesses by a billion pounds a year.

'If you look at all our growth industries – financial services, creative industries, life sciences, digital technology, aggrotech – we are putting in place regulations that make us more competitive, more innovative and faster growing.

'We can do all that because we are outside the EU, so we are cutting all the red tape – not just for small businesses but for all our big growth industries. These are all very tangible benefits of Brexit.'

Mr Sunak also defended himself against claims by former Home Secretary Suella Braverman that he had reneged on a 'deal' to implement key policies, in return for her backing his leadership bid. 'Of course you have conversations with people when you are in a leadership election and not just Suella,' Mr Sunak said. Is he worried about her producing proof of the deal? 'That's a question for her. I'm getting on with actually delivering things'.

Ms Braverman also used an interview with The Mail on Sunday last week to accuse Mr Sunak of a 'lack of moral leadership' over the failure to clamp down on the worst excesses of pro-Palestinian demonstrations over the war on Gaza.

However, the Prime Minister reveals that new laws could be on the way if the police are deemed to be unwilling or unable to tackle the issues using their existing powers.

He said: 'The police already have extensive powers to do that and they should be using them.

'I've been clear with the police. They are operationally independent of government and that has been the tradition in this country, so you do have to respect that – but I've been very clear with Mark Rowley [the Metropolitan Police Commissioner] that we do hold them accountable for making sure that people who break the law feel the full force of it.

'That's how our country works and that's how it should continue to work.

'If there are further powers that we all collectively decide are necessary, then we will bring them forward. That is the conversation we're having.'

Ms Braverman's departure coincided with the marmalade-dropping announcement that David Cameron would be returning to the Government as Foreign Secretary. It is clear from the Prime Minister's words that plans for the move had been gestating for some time. Mr Sunak said: 'I was talking to David quite a bit over the situation in Israel and I think having someone of his stature and experience would be of enormous value. It was a credit to him that he wanted to serve – and he also wants to help me win an election.'

Critics have suggested that the move risks making Mr Sunak look subordinate, but the Prime Minister says that his predecessor knows who is boss.

'He's been absolutely great. It speaks enormous volumes about his character and his commitment to service that he is excited and willing to come back and do this job at an incredibly important time.

'He is an enormous asset to our country and he is an enormous asset to me. I am very delighted to have him back and he is already making a difference'.

As the Nissan robots moved noiselessly around him, I asked Mr Sunak if he is enjoying running the country at a time when his increasingly factional party is 20 points behind in the polls.

His answer does not include the word 'yes'.

He said: 'Look, it's a great privilege. Is it a difficult time to do it? Of course it's a difficult time to do it, but I'm heartened that we're making progress – and crucially on the economy, which is always the most important thing.

'It's the foundation of everything else we want to achieve. Compared to when I took over we have made real progress: we've turned a corner and we can now change gears.'

Tonight, responding to Mr Sunak’s remarks, a spokesman for Mr Farage said: ‘The odds on Nigel Farage becoming the next Tory leader went from 40/1 to 20/1 after this I’m a Celeb this week. Who knows, he might end up winning both.’