Finally, after six long weeks, the final 24 hours of campaigning is upon us. Rishi Sunak and Sir Keir Starmer will be dashing around the country as they make their final pitch to voters.

The prime minister, who may well be out of that job in less than 48 hours, will be sticking to Tory territory in Hampshire and the South East.

The man who is looking almost certain to replace him – Sir Keir – will be touring the three nations of the UK where he is fielding candidates, as he begins the journey to Number 10 via Wales, Scotland and England.

In the Labour camp, they are still intent on turning out the vote and assuming nothing.

One insider suggests to me there are still, as polling day arrives, 60-70 seats which are a “toss up and could go either way”. But there is a quiet admission too that, after four election defeats on the bounce, Labour’s time has finally come.

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But this likely victory – if/when it happens on the night – will require a double take, even if there has been a lack of jeopardy for Labour in this election campaign as the Conservatives failed to shift the polls.

That’s because the scale of the achievement is quite simply astonishing. Labour put in its worst performance since 1935 at the last election, returning just 202 MPs as Boris Johnson won the biggest Conservative landslide since the days of Margaret Thatcher.

Pretty much everyone in the party, bar Sir Keir and his campaign chief Morgan McSweeney, believed Labour would be locked out of power for a decade. The Labour leader told me repeatedly he could turn it around in one term. I thought he was wrong – it now looks like he’s about to be proved right.

And Sir Keir’s three-nation dash is designed not as a victory lap, but a signal of intent because it symbolises how he has repeatedly said he wants to govern, for the whole of the United Kingdom: “Country first, party second” is his common refrain.

He says he wants to be a prime minister that can bring the country back together after the Scottish referendum, Brexit wars, partygate and more latterly the Tory wars and hopes the contours of an election win on Thursday night will be the first step.

Labour’s internal polling points to the possibility that the party could become the largest party by vote share and even seats – although Scotland looks very touch and go – in all three nations for the first time in 24 years. Sir Tony Blair was the last Labour leader to pull that off, in his second landslide of 2001.

But his team are acutely aware that a victory on Thursday is just the end of the beginning and the hard work begins.

Mr Johnson is a shining example of a leader who appeared to have redrawn the political map only to find out that his landslide was built on very shaky ground.

The coalition of voters he amassed to “Get Brexit Done” and keep out Jeremy Corbyn melted away for a myriad of reasons, not least his own conduct in office and a failure to deliver on Brexit promises to level up the country and control immigration.

“If you go from having 200 seats to 360 or 370, you can travel that far again in the opposite direction,” says one Labour insider.

“It is in your hands, but you cannot assume that a possibly big majority means anything in the next election. We are going to have to work extremely hard to keep those votes and to try and get those who don’t vote for us to vote in the future.”

Because what Sir Keir’s team are also acutely aware of is that their victory is predicated, in a large part, not on what the Labour leader is offering but a collective sentiment in the country that voters want the Conservatives out.

Wherever I have travelled in this campaign, I cannot find a voter with a positive view of this Conservative government, with polling showing three out of four voters are dissatisfied with it.

It is difficult to reconcile the fatality of the blow that could be landed on the Conservatives by an opponent wielding the weapon. Sir Keir has nowhere near the favourability ratings of Sir Tony or even Lord Cameron, but could be heading for a big majority nevertheless.

But it also means that if Sir Keir manages to seal the deal with the voters in a meaningful way on Thursday night, he could find himself in the shortest of PM honeymoon periods.

He might be able to pick up a wide base of support, but, as his team acknowledge, it could be very shallow too.

“For some voters, all they want to do is get the Tories out. So we have to win them over again in office in order to try to win them over again at the next election,” says one senior Labour figure.

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It will, Labour insiders concede, take time. The scale of the victory – be it two figures or over 100 – won’t change the reality that Sir Keir has sold a cautious mandate to the country. “Whatever the upper number we could win, it doesn’t change how much money we have available to spend,” cautions a Labour operative.

“When Labour figures talk about being more radical, they mean tax more, perhaps spend more. But that is not the change we are driving at, we have to change people’s lives by growing the economy and it will be the same whether a majority came in at 50, or 80 or over 100.”

Another figure close to Sir Keir puts it like this: “A big Labour majority does not boost public finances, but it gives you a mandate for what you are elected on and it makes it important to stick to that agenda.”

But Sir Keir will want to show he’s hitting the ground running.

The annual summer recess will be the shortest in memory, as the summer sitting is extended to the end of July and MPs are asked to return on 2 September. There will be a bumper King’s Speech on 17 July laying out Sir Keir’s legislative plan and a big house building announcement from deputy Labour leader Angela Rayner in the weeks after victory.

As for the Conservative Party, it will have to weigh up what comes next as contenders for the leadership line up to replace Mr Sunak.

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One former cabinet minister insists Mr Sunak should stay on until a new leader is elected in time for the Conservative Party conference at the end of September. Those who know the prime minister well say only he’ll do the right thing and is not a man to cut and run.

Mr Sunak took the gamble in May to call the summer election, and now it looks like Sir Keir will reap the rewards.

He is poised to be the first Labour leader in nearly three decades to win from opposition and lead the first Labour government in 14 years.

That makes the win historic, as any change of power between parties always is. Whether Sir Keir’s victory will prove as consequential for the United Kingdom as the landmark governments of Clement Attlee in 1945, Margaret Thatcher from 1979 or Tony Blair’s three terms remains to be seen.

He’s still got it. Boris Johnson may have left it late before coming to the party – the Conservative Party, that is – but his 11th-hour rallying cry to the Tory faithful was vintage Boris and just like the old days.

It was the kind of shambolic, chaotic but barnstorming box office performance that he used to give at packed Tory conference fringe meetings when he was the king over the water and greeted like a rock star by his adoring fans.

Back then he used to upstage and humiliate David Cameron and then Theresa May.

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This time his victim was Rishi Sunak, who Mr Johnson’s cheerleaders accuse of knifing him in the back and leading the charge to oust him.

Et tu, Brute? More like Et tu, Boris. As well as answering the call in the Tories’ hour of need, he’d clearly come to settle some old scores, defend his record and remind the Tory faithful he hasn’t gone away.

And he certainly did all of those.

But while Tory activists who turned out at nearly 10pm adore him, is he still a vote winner? Or for undecided voters, is he a reminder of partygate, sleaze and Tory chaos?

But he was there on his terms, as he made clear.

Mr Johnson made a point of beginning his speech, from scribbled notes on crumpled paper, by saying he’d been asked to speak at this rally.

In other words, Mr Sunak had begged him to come to his rescue at the end of a disastrous Tory election campaign. He wasn’t going to offer. He wanted Mr Sunak to grovel and beg.

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There wasn’t a word of praise for Mr Sunak in his speech. No handshake, either.

There may have been other speakers – first Michael Gove and later Mr Sunak – but this was the Boris show and a one-man show.

Although the PM made perhaps his most punchy speech of the campaign when he spoke after him – why leave it so late? It was Mr Johnson who was the star of the show, topping the bill, obviously, and had the Tory faithful screaming his name.

‘Past Starmer’s bedtime’

After a warm-up speech by Mr Gove and then a low-key announcement which seemed to take the audience by surprise, the star turn shuffled on to the stage in an ill-fitting suit, hair unkempt and uncut for weeks and considerably heavier than in his Number 10 days.

When did he last visit a barber?

He always messes up his unruly mop of blond hair before a speech. All part of the act. The late Ken Dodd used to do that. Fans would say Boris the comedian is just as funny as the man from Knotty Ash.

What a mess he looked, though. Not that the audience cared. They chanted “Boris! Boris!” just like they did when he was the darling of the conference fringe.

He began – predictably – with a gag at Sir Keir Starmer‘s expense, the man he used to call “Captain Crasheroonie Snoozefest” at prime minister’s questions.

He thanked the audience “for coming so late tonight to this venue, way past Sir Keir Starmer’s bedtime”. Boom, boom! The Labour leader will have to live with jokes about his 6pm Friday curfew for some time.

“I was glad when Rishi asked me to help,” he claimed. “Of course I couldn’t say no.”

Well, probably not. But those Red Wall Tories now facing defeat on Thursday will have wished he’d answered the call a lot earlier in the campaign.

Turning on Farage

We got the usual Johnson defence of his handling of the pandemic and the roll-out of the vaccines. And he boasted several times, not surprisingly: “We got Brexit done.” It was “a proper Brexit”, he said, a “Brexit government”.

Maybe. The audience loved all that, but why are so many Tories turning to Reform UK if it was such a triumph?

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Next, Sir Keir was ridiculed as “Jeremy Corbyn’s disciple” and accused of “taking EU law by dictation” and “poor old Starmer” was “reluctant to explain the difference between a man and a woman”, he claimed.

Then he turned on Nigel Farage, something Mr Sunak and his senior ministers should have done weeks ago.

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Reform UK was “full of Kremlin crawlers” and Putin’s “pet parrots”, he said. “Shame on them!” he declared, to wild applause.

And then a typical Johnson gag: “Don’t let the Putinistas deliver the Corbynistas!”

Vintage, yes. Funny, naturally. A great showman, definitely.

But is he still an asset, when so many voters appear to want to punish the Conservatives for his time in Downing Street rather than blame Mr Sunak for Tory failures?

Whatever voters think of Boris Johnson, his last-minute cameo has almost certainly come too late to save the Conservatives from the heavy defeat the polls are predicting.