The moment the exit poll dropped will be forever imprinted on the memory of Labour’s Jonathan Ashworth.

“Because I’m such a political nerd, I could quickly work out what seats we were losing,” said the shadow health secretary. “Through my head was flickering all the faces of colleagues who I knew were probably not going to survive the night.”

Boris Johnson went on to secure an era-defining 80-seat majority while Jeremy Corbyn’s Labour faced its worst general election defeat since 1935. 

“I hadn’t seen any internal polling,” he added. “I didn’t expect the scale of the defeat.” 

Ashworth, who tried to convince voters their NHS was “for sale” in a US-UK trade deal, has many regrets about the election campaign, but does not dodge his share of the blame. 

“Of course [Jeremy Corbyn] came up on the doorstep, but there’s no point blaming it on one individual,” he said.

“We will be remembered as the shadow cabinet that delivered the worst defeat since the 1930s. We can’t get away from that.”

Handing Johnson an early election was a “massive strategic error”, he says, but it was one the party could not escape once the move was supported by the Lib Dems and SNP. 

“Every general knows that you don’t fight on the turf the other general wants you to fight on,” he added, admitting Johnson’s “get Brexit done” broke through early on. 

Turning to his own brief, Ashworth said that – instead of highlighting the risks of a Donald Trump trade deal – Labour should have put everyday NHS failures “front and centre” and “been consistent in the same way that Boris Johnson was consistent”.

“When he wasn’t talking about Brexit, he was talking about the new hospitals and extra nurses,” said Ashworth. 

“I think the concerns about the way in which a trade deal locks in the liberalisation of contracting in the NHS are legitimate, but I think in the end people either understand it or didn’t worry about it. 

“The British public didn’t think it was the most relevant issue for them in their experience of the NHS. We should have been putting much, much more emphasis on waiting lists, on cancer waiting lists and children’s mental health.” 

The battle for Labour’s future is on, with shadow Brexit secretary Keir Starmer, campaigning Wigan MP Lisa Nandy and shadow business secretary Rebecca Long-Bailey in the running to be the next leader.

Ashworth is frustrated that the leadership contest will drag on until April 4, however, as he is keen to “get back in the ring” and take Johnson on over his response to the floods and coronavirus. 

“This is clearly becoming very, very serious now,” he says. “We are likely to have more coronavirus cases in this country – there’s no question – and we know the NHS is under considerable strain.” 

Last year, the NHS recorded the worst A&E waiting times on record, while 17,000 beds have been cut since 2010 and the health union Unison has estimated there are more than 100,000 staff shortages. 

“Should we see a huge escalation of coronavirus cases in this country,” he said, “I think there is a legitimate question over whether the NHS has enough resources to cope.

“If I was the health secretary I would be banging on the door of the chancellor asking for an emergency boost to funds as a contingency.”

Ashworth is backing Nandy for the Labour leadership, as he agrees with her analysis that Labour needs to recover its prospects in towns. 

“So we’re still building up majorities of 20,000-plus in the cities like Leicester, Newcastle, Manchester and Leeds,” he says.

“But there’s no point me in me having a massive majority of 20,000 if we can’t win back Mansfield, and we’ve lost Derby North and we’ve lost Bolsover.” 

He regards Nandy as a “fantastic media performer” and “the real left-wing voice in the contest”. 

“When you look at her interviews with Andrew Neil and Piers Morgan, I’d go so far to say they left those interviews looking a bit bruised,” he said. 

“And isn’t it isn’t it nice to see a frontbencher really knocking it out of the park in a high pressure media interview? That hasn’t always happened recently.” 

She was also one of the leading figures for a Brexit compromise, unlike the clear favourite, Starmer, who is often accused of pushing too hard for Remain. 

Ashworth pointed out, however, that the shadow cabinet faced unrelenting pressure from from its pro-EU members. 

“People now saying that [Starmer] bounced us into a position actually have to explain to us why we should have ignored party conference,” he said.

“Is their position that we should have stifled Labour Party democracy? Because often on many of the other issues that we face, we’re told that party members have to be in charge of policymaking.” 

He rejects criticism that Starmer, who previously led the Crown Prosecution Service, could prove to be a grey leader in comparison to Johnson. 

“I think he’s impressive when you look at his background – for example his handling of the McLibel trials and on human rights – and the way he has forensically taken the Tories apart on Brexit in the House of Commons,” he says.

“I don’t think he’s boring at all. I think he can be quite exciting. But then it’s also about the team is going to put together around him.”

After years of divisions under Corbyn, he is hopeful the party can move on regardless of who emerges victorious. 

“These are perilous times for the Labour Party,” he said. “We’ve got to pull together.” 

He adds: “My worry is we are forgetting how important it is to get back into government. If we lose next time, that’s probably the longest period we’ve ever been out of government in our history.

“We have to win again. And that’s not about ‘compromise’ or any of these things that get bandied around.

“If we don’t get back into government, we’re not failing ourselves as individual politicians and we’re not failing ourselves as people who go to the local CLP meeting – we’re failing the working class, we’re failing the people are sleeping on the streets and we’re failing the children who are growing up in poverty.” 

The Leicester South MP is hopeful of remaining shadow health secretary but admits the new leader “might sack me”. 

“There’s loads of really, really good shadow ministers who are knocking on the door of the shadow cabinet and really I would encourage and hope the new leader is looking to them.”  

Before entering parliament, Ashworth worked as an adviser to Gordon Brown and Harriet Harman but says people incorrectly see him as on the party’s right-wing. 

Should Bernie Sanders win the Democratic nomination, Ashworth says he will go to America to campaign for him. 

“I always get so written up as some sort of moderate,” he said.

“But I suppose I’m more of a curious figure – because the policy agenda on public services, economics and austerity is an agenda which I’m very enthusiastic about, and one that I would not want to see a future move away from,” he says. 

“I think the work Jeremy did in pulling the Labour Party in that direction was correct and welcome.

“We cannot go back to the days of splitting the difference with the Tories and printing anti-immigration slogans on pieces of crockery.” 

He says the Tories will stumble and Labour has “got to be in the ring” and ready. 

“I think we’re more likely to see Matt Hancock riding Shergar at Newmarket than we are a social care plan. 

“But it doesn’t matter if I buy it – it matters if the British public buy it.” 

He added: “It’s a four- or five-year parliament and, even though the Tories have got a big majority, I think they’re there for the taking. 

“They’re talking about levelling up, but are they really going to resolve the issues that people have, such as child poverty or homelessness? 

“At the next election, people will start saying: ‘Hang on a minute – you promised us 40 brand new hospitals. He promised all these nurses, a social care plan and that you’ll get waiting lists down. Where is it?’

“I think there will be opportunities for the Labour Party to challenge them in the coming years.

“He’s told the British people that he is going to build them 40 new hospitals, that he is going to deliver them 50,000 extra nurses, and that he is going to get waiting lists down.

“Well, the British public will probably give him the benefit of the doubt for the next few months, but certainly by the next general election, if they can’t see those 40 brand new hospitals, or if there’s no social care plan, there aren’t 50,000 extra nurses working in the NHS, I think the British public in these red wall seats will have something to say about that.”