DAN HODGES: For Team Rishi, Boris is now a real threat… For Team Keir, he's the only threat 

The Shadow Minister had a twinkle in his eye. ‘Wait for Keir’s speech tomorrow,’ he told me. ‘There’s a fun little rabbit in it. He’s going to wind up Boris and his people.’

The rabbit turned out to be the Labour leader’s announcement that he would place a Take Back Control Bill at the centre of his first King’s Speech if he becomes Prime Minister. The pledge itself fell flat, with no details provided about what this supposedly transformational piece of legislation would actually contain. But the political symbolism was clear. ‘I’m coming for Boris’s Blue Wall voters!’ Starmer was declaring.

The next day, I bumped into another Shadow Minister. We chatted about the general political landscape, with him offering an upbeat assessment of Labour’s chances. Then he asked with a hint of trepidation: ‘What’s going to happen with Boris? Do you think they might try to bring him back?’

The official line from Team Starmer is ‘no complacency’. The next General Election – due in 2024 – will be a tight battle. Even securing a small majority will be a struggle. Nothing can be taken for granted.

¿I¿m coming for Boris¿s Blue Wall voters!¿ Starmer was declaring. Pictured: Giving a speech during a visit to UCL at the Queen Elizabeth Olympic Park, London

‘I’m coming for Boris’s Blue Wall voters!’ Starmer was declaring. Pictured: Giving a speech during a visit to UCL at the Queen Elizabeth Olympic Park, London

However, the private line is different. Senior Labour strategists are convinced that Rishi Sunak is already a busted flush.

‘For some reason Sunak has decided to adopt a “steady as she goes” approach to the worst economic and social crisis since the 1990s,’ one told me. ‘If the Tories want to turn things round, they need to try something radical. Even Liz Truss understood that. But Sunak’s sitting back and playing safe. And that’s fine with us.’

Which is why if Boris Johnson isn’t directly in Starmer’s sights, he’s in his head. There is nothing Sunak has done since becoming PM that has given Labour’s leader sleepless nights. But the thought of a dramatic return for the Tory Party’s favourite Prodigal Son most certainly does.

‘I looked back at our focus groups from around the time Boris resigned,’ one Shadow Minister explained, ‘and there were a group of 2019 Labour-to-Tory switch-voters who were saying, “That’s it, Boris is dead to me. He’s let me down. I won’t vote for him again.” And there were enough of those to just give us a majority.’

But he added: ‘There was an even larger group – and it was growing – who were saying, “Look, we know who Boris is. We don’t agree with what he did on Partygate. But he got us through Covid. He delivered the vaccine. He’s done OK on Ukraine. Just get off his back, and let him get on with it, and see if he can deliver for us again.”’

Another Labour strategist framed it more graphically. ‘The Tories getting rid of Boris was gold dust for us. It brought into play this whole group of voters who were out of reach. There are a clump of constituencies we thought we could win that we now think we should win. And that means we can start prioritising in terms of resources and leadership visits.’

There is, of course, an element of mischief-making attached to the candour with which Starmer’s allies talk up their fear of Boris’s return. As one commented to me: ‘Sunak isn’t going to be able to get Boris off his back. The months between now and May’s local elections are going to be taken up with endless speculation about whether Boris will make a move or not.’

It’s more than just speculation. As Nadine Dorries, one of Boris’s closest friends, bluntly sets out in today’s Mail on Sunday: ‘The future of Conservative MPs rests in their own hands and they have a simple question to ask themselves: Do they want to remain as MPs, or not?

‘It is an undeniable fact that, with Boris at the helm, more of them will return to Westminster following a General Election than with any other individual leading the party… It’s bring back Boris or die.’

Such a scenario is creating a strange convergence between the interests of Sunak and Starmer.

Inside No 10, there’s a growing realisation that Boris represents a genuine threat. Inside Starmer’s office, there’s a belief he is the only threat.

As a result, some Labour MPs think parts of Downing Street have decided the time has come for the Boris threat to be neutralised – with their assistance. ‘We’ve been putting in some parliamentary questions that raise issues about Boris and his time in Government,’ one Labour MP told me, ‘and until now, such questions would have been blocked. But suddenly we’re getting quite a lot of good information. It’s almost as if someone’s decided, “If you want to kill off Boris, we’re not going to stand in your way.” ’

Meanwhile, there’s another reason why some on the Tory side believe the ‘Johnson sore’ cannot be allowed to fester for much longer.

Sunak’s focus is solely on finding a way to grapple with the myriad crises besieging his Government.

Senior Labour strategists are convinced that Rishi Sunak is already a busted flush

Senior Labour strategists are convinced that Rishi Sunak is already a busted flush

A friend of the PM told me: ‘He’s just not stopping. His officials can’t believe the amount of time he spends buried in his papers. He was on a plane the other day, but when his dinner came he just waved it away. He worked through the entire flight.’

But around him the war-gaming of the next Election is already under way. The political gurus who delivered victories in the Brexit referendum and the 2019 Election are staring at their laptops and whiteboards, trying to devise a strategy to deliver one more upset. And they’re struggling.

‘The problem is that we’re trying to put together a plan for winning the next Election,’ one Cabinet Minister confessed, ‘but we don’t know who the plan’s for.

‘If it’s Rishi, we’ll have to follow a particular strategy. If it’s Boris, we’ll need a completely different one. But it’s impossible to come up with adverts, attack lines or manifesto commitments that work for both men because they’re such completely different politicians and personalities.’

To an extent, Labour have a similar problem. They’re putting together a campaign aimed at defeating Rishi Sunak. And if Boris were to return to No 10, their own plans would have to be torn up.

But unlike their Tory counterparts, Starmer and his team aren’t conflicted about which opponent they would prefer to be up against in 2024.

‘Keir’s not a demonstrative man,’ one of his friends confided, ‘but you should have seen him the day Boris announced he was going to resign. He was walking round the office high-fiving everyone.

‘I’d never seen him do a high-five in his life.’

Many Tory MPs view the prospect of Boris returning with dread. ‘It can’t happen. It won’t happen. I will do everything in my power to make sure it doesn’t happen,’ one Cabinet Minister told me.

That antipathy may be well founded. A Boris leadership challenge would inject fresh chaos into the heart of Government. And voters are unlikely to look kindly at yet another bout of Tory infighting – one that could result in a fourth Prime Minister in the space of a year.

But there’s no doubt who Labour fear most.

‘With Rishi in No 10, we are heading into the long, cold and brutal wasteland of thankless opposition,’ Boris’s cheerleader Nadine Dorries writes today. Sir Keir Starmer will wholly agree.