Rishi Sunak endured a torrid grilling from journalists as he launched the Tories’ underwhelming election manifesto.

The 76-page document only contained one major new policy – a plan to abolish National Insurance contributions for the self-employed.

The party has also vowed to cut another 2p off the overall rate of National Insurance, despite previous reductions doing nothing to improve their poll ratings.

But the prime minister risked a backlash from Tory right-wingers for refusing to commit to removing Britain from the European Convention on Human Rights.

In a clear sign that he expects to lose on July 4, Sunak begged voters not to hand Keir Starmer a “blank cheque” in government as he once again repeated his hotly-contested claim that Labour will put up taxes by £2,000 per household.

Although he got a warm reception from the Tory ministers and supporters gathered at Silverstone Grand Prix race track, the PM was monstered during a question and answer session with reporters.

ITV political editor Robert Peston said: “Tories in government since 2010 have been pushing up the tax burden to levels we haven’t seen since the late 1940s. Why should anyone believe you when you say you’re going to cut tax?”

BBC political editor Chris Mason told him: “For much of the last 18 months, you’ve tried everything to try and revive Conservative fortunes and not much appears to have worked.

“Could we rename this document as your last chance saloon? What is in this to shift things that perhaps haven’t shifted up until now?”

Sunak told him the country had “turned the corner” thanks to his leadership.

He said: “There is a clear choice at this election. We are the only party putting bold action on the table that will transform our country.

“Labour have nothing to say about the problems our country faces and how best to address them. Nothing. Keir Starmer is asking for a blank cheque and he will not tell people which taxes he is going to put up that are ultimately going to cost them £2,000.”

Ben Riley-Smith, political editor of the Daily Telegraph, asked the PM: “What do you say to those who say the manifesto isn’t ambitious enough and this won’t be a game-changer?”

Sky News political editor Beth Rigby said: “A recent poll shows only one in six voters thinks you won’t raise their taxes, compared with one in four for Labour.

“Labour’s more trusted on tax than you at the moment – that’s your record as chancellor and now prime minister. I’m sure that’s a disappointment to you.

“Haven’t you blown it now, whatever you say?”

But Sunak insisted he was “very proud” of his record as chancellor, pointing out that he had brought in the furlough scheme during the Covid pandemic.

He said: “We will always be there to protect this country through difficult times.”

Labour campaign chief Pat McFadden said: “This Conservative manifesto is a recipe for five more years of Tory chaos.

“After 14 years in power, the prime minister’s desperate manifesto is stuffed full of unfunded spending commitments. The prime minister that was brought in to be the antidote to the chaos of Liz Truss has instead become the next instalment of the same thing.”

It is perhaps fitting that the Conservative Party is ending this parliament just as it has spent much of the previous five years: bitterly divided.

Reactions to Rishi Sunak’s shock decision to call a snap election range from astonishment to anger to grim resignation.

“No one sees the reason for the rush and feel like he has lost the plot,” one senior Tory told HuffPost UK. “None of us are ready for this.”

Support was also far from unanimous as the prime minister told his cabinet on Wednesday afternoon that he had decided to go to the country on July 4.

But the PM’s mind was made up, despite the fact that Labour remain 20 points ahead in the opinion polls and election experts all agree that the Tories are heading for a historic defeat.

One minister said most Tory MPs are simply resigned to their fate, and hit out at his malcontented colleagues.

He said: “In the tearoom I see cheerful stoicism all round. I suppose the whingers are the ones who prefer a leadership contest to a general election.”

Another MP was happily laying bets that the Conservatives will still emerge as the largest party in the Commons.

“I’m glad the phoney war is finally over and we can get on with the election,” the MP said. “We will fight for every vote.”

A senior Tory aide summed up the schizophrenic nature of MPs’ response to Sunak opting for a summer poll.

“A week ago they all wanted it over and done with and now they are furious it hasn’t gone longer,” he said. “I strongly suspect vast majority are resigned to fate and don’t feel that strongly about it.”

The sight of a bedraggled Sunak announcing the election date in the pouring rain outside No.10 has summed up the Tory campaign so far.

That gaffe was further compounded on Friday when the PM inexplicably visited Belfast’s Titanic Quarter, thereby linking him in voters’ minds with the world’s most famous sinking ship.

Nevertheless, Tory bosses want to run a presidential campaign, urging voters to stick with the man who bankrolled the government’s response to the pandemic rather than take a risk with the untried Keir Starmer.

The problem with that approach, however, is that voters already seem to have decided that they want Sunak and the rest of his government ejected from office as soon as possible.

Chris Hopkins, political research director at pollsters Savanta, said: “The prime minister already had a mountain to climb in this election, with a massive polling deficit and Labour leading them on every policy issue.

“On top of this, Sunak himself is hugely unpopular with the public, and based on our research, so are his most senior ministers.”

Polling done by the More in Common think-tank in the wake of the election announcement, shared exclusively with HuffPost UK, shows that only 29% of voters see Sunak as an asset to his party, compared to 46% who don’t.

Jenna Cunningham, More in Common’s research and data analyst, said: “There’s no doubt that Rishi Sunak was a popular Chancellor, especially after the furlough scheme, but questions remain about the effectiveness of the current presidential campaign strategy when only three in ten voters think he is an asset to the Conservative Party.

The general feeling among senior Labour figures is one of bafflement at Sunak’s decision to call an election now rather than wait until the autumn.

“I don’t understand the logic,” one adviser to Starmer told HuffPost UK. “If he’d gone for May he could at least have masked the local election results. Summer seems to be the worst of all worlds for them.

“It could be that the economic conditions are much worse than they thought they were and Rwanda isn’t going to work as well, so he’s decided they couldn’t hang on any longer. But you can see why Tory MPs are furious about it.”

One word we are all going to be sick of hearing over the next six weeks is “change”. It was on Starmer’s lectern as he responded to the PM’s announcement and will be emblazoned on thousands of Labour posters on the run-up to polling day.

“It’s very important that voters know that the only way to end the chaos of the last 14 years is to vote Labour,” said one party stretegist.

“The fact that the Tory campaign has so far been so chaotic – his ludicrous speech in the pouring rain and their MPs all saying he shouldn’t be doing it – just helps us to reinforce that message.”

At the moment, Labour’s main opponent seems to be complacency.

“We’re going to fight this campaign as if it’s still neck and neck,” said one insider. “We will be fighting to win day by day, week by week

“We need to fight as if the polls don’t exist.”