Boris Johnson was unleashed as the Tory party's secret weapon last night, answering the Prime Minister's calls as he warned undecided voters a Labour landslide would be 'pregnant with horrors'.

With just a day of campaigning left before Brits go to the polls, the former Prime Minister put to bed any rumours of a feud with Rishi Sunak in a last-ditch attempt to cling on to blue seats.

Stepping out into the central London rally last night, Mr Johnson was surrounded by ardent supporters who clapped, whistled and chanted his name as he made a long-awaited return into the spotlight.

During his impassioned speech, Mr Johnson called on voters flirting with backing Reform to 'draw back from the brink' to stop Sir Keir Starmer secure his party's projected supermajority tomorrow.

He labelled Nigel Farage as a 'Kremlin crawler' and unleashed attacks on Labour's 'mandatory wokery' and 'uncontrolled immigration', bluntly adding that people who 'have a few thousand to spare' and 'actually want higher tax' should vote red.

Mr Johnson went on to make a dig at Sir Keir Starmer saying it was 'way past his bedtime' after the Opposition leader admitted he tries to avoid working past 6pm on Fridays to spend time with his family.

The former PM was not expected to make a return on the general election campaign but had decided to make a dramatic eve of the poll intervention after becoming 'vociferously angry and upset' over a predicted Labour supermajority. 

Hinting at the 'trivial' differences between himself and his former Chancellor Mr Sunak, Mr Johnson said he was a 'glad when the PM asked for help' and 'could not say no' because they both 'love our country'.

The former Mayor of London hit out at Labour's plans to hike taxes and said the party would not take a firm stance against Vladimir Putin, following his unjust invasion of the war in Ukraine. 

He went on to criticise Sir Keir for not being able to explain 'the difference between a man and a woman'. 

'He sits there with his mouth open like a stunned mullet,' he said. 

Mr Johnson, who led the Tories to a landslide victory in 2019 against Jeremy Corbyn, added: 'They can achieve nothing in this election except to usher in the most left-wing Labour government since the war with a huge majority, and we must not let it happen.

'Don't let the Putinistas deliver the Corbynistas. Don't let Putin's pet parrots give this entire country psittacosis - which is a disease you get by the way from cosying up to pet parrots.

'Friends, if you actually - everybody if you actually want higher taxes next week, this year, if you feel you've got a few thousands to spare, then vote Labour on Thursday. If you want uncontrolled immigration and mandatory wokery, and pointless kowtowing to Brussels again, then go right ahead, make my day, vote for Starmer.

'But if you want to protect our democracy and our economy and keep this country strong abroad by spending 2.5 per cent of our GDP on defence which Labour still refuses to commit to, then you know what to do, don't you, everybody?

'There's only one thing to do - vote Conservative on Thursday my friends and I know you will. I know you will.'

Mr Johnson's intervention is said to have come after the Prime Minister sent him a personal message last week asking him if there was anything at all he could do to help the final days of campaigning.

While Mr Johnson has used his weekly Daily Mail column, social media and personal letters to electrify the flagging campaign he was largely kept a low profile on the campaign trail.

Yet Tory strategists brought the former PM back into the spotlight, hoping he could electrify a flagging campaign and galvanise former Conservative voters to keep the faith when they head to the polls on tomorrow.

Mr Johnson's appearance was a closely-guarded secret known only to a tiny handful of No10 officials. Even cabinet ministers attending last night's rally were kept in the dark. 

Last night a friend added: 'Boris loves the Conservative party and has always believed in being a big person. So when the call came to help, of course he answered.

'He's hoping that if he can give the Tories such fulsome backing after the way he's been treated by the party other disgruntled supporters will do the same too.'

Following his speech, Mr Johnson welcomed the Prime Minister onto the stage who urged voters not to 'surrender to Labour' and 'fight for every vote'. 

Addressing the known tensions between himself and Mr Johnson - as well as wider strains within the Tory party - he told the audience: 'Isn't it great to have our Conservative family united, my friends?'

'Just think, just think, it was just the other day when Keir Starmer was saying that Jeremy Corbyn would have been a better prime minister than Boris,' he added.

'Shameful. Can you imagine what that would have meant for Ukraine? What it would have meant for our country's security, our defence, the damage it would have done to our economy?'

The PM - who is currently spending his last hours of campaiging on a whirlwind tour across the UK in a bid to gain 130,000 extra votes - told undecided voters they had '48 hours to save Britain from a Labour government'.

'I know you are tired, but we have to give it one last push. We have to fight for every vote. We have to fight for our values.' 

He concluded his speech by telling the audience: 'I love my country. My story would not be possible in any other country.' 

Boris' intervention came as:

• Mr Sunak said that just 130,000 voters in marginal seats could change the course of the election and prevent an 'unchecked' Labour government.

• Polling by Lord Ashcroft suggested Labour's huge lead could be trimmed to single figures if Tory voters return to the fold in the next 48 hours.

• Home Secretary James Cleverly branded Labour's immigration plans a 'con job' and warned the party would introduce an amnesty for tens of thousands of illegal migrants.

• Sir Keir insisted a Labour landslide would bring stability and be 'better for the country'.

• Another Reform candidate defected to the Tories with a blast at the 'racist, misogynistic, and bigoted' views of other senior figures.

• The PM and Labour leader spent the day criss-crossing the country in a bid to energise supporters to get out and vote tomorrow.

Mr Johnson last night's said he had doubts about whether polls showing a giant Labour majority were accurate, saying he had faith that people would 'still show more sense on Thursday'.

But he said traditional Conservatives 'cannot just sit back as a Labour government prepares to use a sledgehammer majority to destroy so much of what we achieved'.

He warned that Sir Keir would water down Brexit, restore free movement and 'make us nothing but the punk of Brexit - taking EU law, but with no say in how it is made'.

And he warned a Labour agenda would involve 'whacking up taxes on pensions and property, persecuting private enterprise, attacking private education and private healthcare - with all the pointless extra burden that will place on the taxpayer'.

He mocked Sir Keir as the former 'disciple' of Jeremy Corbyn who is so in thrall to Left-wing activists that he looks like a 'stunned mullet' when asked to explain what a woman is.

And he savaged Nigel Farage for his praise of Vladimir Putin's skills as a political operator.

Mr Johnsons warned that Reform 'can achieve nothing in this election except to usher in the most left-wing Labour government since the war, with a huge majority,' adding: 'Don't let the Putinistas deliver the Corbynistas.' 

Mr Johnson's appearance attracted criticism from the opposing parties.

The Lib Dems deputy leader Daisy Cooper said last night: 'This is an insult to everyone who made heartbreaking sacrifices during the pandemic. 

'Rishi Sunak has reached a desperate new low, turning to a man who discredited the office of Prime Minister and lied to the country time after time. 

'It is time to boot out this tired and sleaze-ridden Conservative Party, and elect Liberal Democrat MPs who will stand up for their communities.'

A series of polls yesterday showed that Labour's poll lead is being squeezed as Reform's vote falls back - but suggested Sir Keir remains on course for a landslide majority.

One Tory insider said: 'The squeeze is on, but it is very late.' A Redfield and Wilton Strategies survey of 20,000 voters found that Labour's lead had been trimmed by four points, but left them still 19 points ahead of the Conservatives.

Polling by Lord Ashcroft published by the Mail yesterday also gives Labour a 19-point lead, with Labour's overall support dipping to 38 per cent - less than Jeremy Corbyn achieved in 2017.

But a mega poll by Survation found that Labour were now '99 per cent' certain to get a bigger landslide than Tony Blair in 1997. 

The survey of more than 30,000 people, predicted that Labour will win a record 484 seats, with the Conservatives reduced to a rump of just 64, narrowly ahead of a rejuvenated Lib Dems on 61. Reform could get 16 per cent of the vote but win just seven seats, the poll found.

In an interview with the Daily Mail, Mr Cleverly said voters worried about the threat of a Labour supermajority can still turn out tomorrow and 'make the opinion polls wrong'.

He acknowledged that some people want to 'punish' the government after tough few years marred by Covid and the war in Ukraine. 

But warned he warned those considering Reform that the urge to give the government a 'slap' could lead to '15 years hard Labour' if they split the vote and give Labour a supermajority.' 

'The vast bulk of votes have not been cast - you can decide what future you want. You can make the opinion polls wrong,' he said.

'The scale of the 'hovering pencil' cohort means the outcome is nowhere near as definitive as some of the commentary has suggested.' He said those toying with a vote for Reform to send a message to the Conservatives should consider whether 'the message you are looking to send, is worth five, 10, 15 years of hard Labour?' 

In a speech yesterday, Mr Sunak will urge voters worried about a big Labour majority to take action to prevent it.

'If you are worried about an unchecked, unaccountable Labour government you can stop that by offering us your support so we can stand up for you and be your voice in the next Parliament,' he will say.

'Your vote will determine whether your MP is just another addition to Starmer's supermajority or a local champion, someone who cares about you and will fight for your area and its needs.

'Do you want an MP who holds the Government to account or one who just unthinkingly backs Keir Starmer and whatever he wants to do?'

Mr Johnson's appearance comes as Sunak began a 48 hour whirlwind tour across the country in desperate appeal to the public as pollsters project that tomorrow, Keir Starmer could win a bigger majority than Tony Blair's landslide win in 1997.

Kicking off the last two days of campaigning, the current Tory leader claimed all the party needed was 130,000 votes to make the difference.

'It's not over until it's over,' Mr Sunak brazenly told downbeat supporters and party activists as they approach the finishing line of a grueling six-week drive for votes. 

His motivating words echoed that of Johnson's who last week jumped up to the aid of his former Chancellor telling voters 'it's not too late'.

'There is still time between now and Thursday for the nation to swerve from the cliff edge,' Daily Mail columnist Mr Johnson wrote on Friday. 'We can collectively come to our senses. We can dodge the bullet.'

The former PM, who resigned almost two years ago, went on to attack Starmer's own 'shockingly low' approval ratings. 

Mr Johnson added: 'Britain is about to jump the points and jink left, abruptly, in what could be a Left-wing socialist supremacy that lasts for a decade or more.

'And yet Starmer's own approval ratings are shockingly low – the lowest ever for an Opposition leader on the verge of entering Downing Street, let alone of a triumph on the scale currently predicted. Poll after poll says the same.'

Mr Johnson's appearance with Mr Sunak comes after the current PM welcomed his predecessor to join him on the campaign trail.

Earlier this year Mr Sunak said the ex-PM could join him as he tries to build support for the Tories. 

Diffusing any concerns of a rift between the two leaders, Mr Sunak told The Sun's Never Mind the Ballots show that he had been in touch with the ex-PM at the end of last year.

He said in April - months before he announced the election date: 'I spoke to him in person at the end of last year and we've messaged since then as well.'

Asked if he would be invited to campaign on doorsteps and in the streets of Britain for the Tories, Mr Sunak added: 'That's a question for him.

'Anyone from the Conservative family who wants to see a Conservative re-elected and who doesn't think Keir Starmer is the right person to lead our country will be welcome on the campaign trail.

'Ultimately that's the choice. It's Keir Starmer or me as Prime Minister after the next election.

'If you want to keep cutting taxes, a more sensible approach to net zero, if you want to tackle illegal migration, then we are the people to do that for you.'

The final MRP study by Survation yesterday, published within the last 48 hours of campaigning, predicted Labour would win 484 seats at this week's general election.

The model, based on polling data from more than 30,000 voters, forecast the Tories would be reduced to just 64 seats in the House of Commons.It means the Tories would scrape into being the official Opposition, with the Lib Dems predicted to win 61 seats.