The UK prime minister hopes the US president can give the remain camp a boost – but it may take more than that

Nothing says modernity, progress and optimism quite like President Barack Obama surrounded by a troupe of young people and talking of the importance of solidarity among nations. At least that is what those running the pro-EU Remain campaign will devoutly hope.

Next weekend, the television cameras will be rolling, the famous smile will be deployed – and the importance of Britain’s continued relationship with the European Union for the next generation will be affirmed by the world’s most powerful man at a “town hall event” in central London.

The charm offensive is being described by Downing Street sources as “Obama Direct” – a rather presumptuous reference to the prime minister’s occasional “Cameron Direct” events. But the deployment of the US president, while undoubtedly a clever move by the Remain camp, speaks also of jitters, worry and perhaps even a degree of desperation.

“Six months ago I didn’t really think we had much chance of winning,” admitted one source at the highest levels of the Vote Leave campaign. “But if things go our way, there is a chance, I think. And things really are going our way at the moment.”

Few would disagree with that analysis. From Iain Duncan Smith’s incendiary resignation over his government’s attacks on the poor and vulnerable to the publication of the Panama Papers, the prevailing wind has been at the Brexit gang’s backs. Jeremy Corbyn’s reluctance until last week to say anything positive about the EU has also helped.

The challenge for the prime minister has always been in winning over the sections of the electorate that cannot stand him. It was a challenge when he was trusted, if not liked. Last week a YouGov poll reported that public faith in Cameron had dropped by eight points since February, to 21%. The number of people who feel Cameron should resign after the referendum has increased by 13 points, to 31%.

On the day Cameron returned from Brussels, proclaiming that Britain’s relationship with the EU had been fundamentally revised, the Remain camp had a 15-point lead. Last Friday (the first day of the official 10-week campaign), polls had the Leave and Remain camps neck and neck on 39%. Former chancellor Kenneth Clarke was typically frank about what it will mean for Cameron personally if things do not go his way.

“The prime minister wouldn’t last 30 seconds if he lost the referendum,” he said. “We’d be plunged into a Conservative leadership crisis, which is never a very edifying sight. Clarke added that the mood within the Conservative party was “dangerously close” to the days of the Maastricht treaty rebellions, in the dog days of the John Major administration.

Downing Street sources say there will be a “step-up” in activity this week. It is understood that the chancellor will make a speech in which he will hail Britain’s trading history and its strength as part of the EU. Grim warnings will be made about the dangers of isolationism, and a document on the economic merits, or otherwise, of EU membership is set to be published this week, as is obligatory under the Referendum Act. George Osborne has already warned that mortgage rates will rise if Britain votes to leave. Much more of that sort of thing can be expected.

But George Eustice, the minister for farming who launched Vote Leave’s campaign in south-west England in front of 150 people at a Plymouth hotel on Friday, believes that Cameron and Osborne are mistaken if they believe the Scottish referendum playbook, in which the fear factor featured prominently, can deliver the same result.

Facebook Twitter Pinterest Boris Johnson addresses supporters at a Vote Leave meeting in Newcastle. Photograph: Owen Humphreys/PA

“I think turnout could be quite a factor in this,” Eustice said. “Among those who want to leave the EU there is more enthusiasm and more clarity about their views and therefore they are more likely to vote. The Remain campaign hasn’t built a passionate case for remaining in the EU; it has just emphasised the dangers of change. I don’t think that is going to get the vote out. In Scotland the turnout was so high because there was an affinity with the concept of the UK. I don’t think there is such an affinity with the EU.”

The decision to set Obama among a young crowd next weekend is pointed. Support for staying in the EU is strongest among young people. The Remain camp need them to get out and vote on 23 June. Yet figures produced by the all-party parliamentary group on democratic participation show that even before the government changed the rules so that every individual, rather than household, needed to register to vote, a quarter (27%) of 18- to 30-year-olds were unregistered.

The Brexit camp has major hurdles to jump as well, of course. Speaking in Newcastle on Saturday, Boris Johnson launched a fresh attack on Cameron for “shamefully” spending £9.3m of taxpayers’ money on a pro-EU leaflet. London’s mayor criticised the “scare” tactics of the Remain campaign as he continued what he has called his northern “Brexit blitz” tour. But the start of his speech was interrupted by hecklers shouting “no Tories in Newcastle”. Cameron will find it difficult to take those on the left with him (and Corbyn will need to raise his game, many in the Labour fold agree) but how much more difficult will it be for Johnson?

Meanwhile on the left of the spectrum, the disappointment with Corbyn’s speech in favour of EU membership last week was keenly felt among the small band of current and former Labour MPs supporting Brexit. Corbyn’s long-time friend John Sweeney, a high-ranking trade union official, claimed that Brexit was in his constituency MP’s blood. “He’s spent 40 years campaigning for Brexit, and only 12 months pretending to be in favour of Remain,” Sweeney said.

Labour MP Kelvin Hopkins added: “Most of Jeremy Corbyn’s agenda would be much more difficult in the EU; if we want to take public ownership of the railways and the post office, most of those issues – one can argue about the rights and wrongs of them – would be more difficult within the regulations of the EU.”

The big question the Vote Leave campaign has failed to answer, and the one that causes it most trouble, will finally be addressed this week. Justice secretary Michael Gove is expected to give a speech on Wednesday sketching out his vision of the UK outside the EU.

The Remain camp has 10 weeks to come up with an inspiring answer as to why the status quo is better. Not all the heavy lifting can be done by Obama, no matter his star appeal.

CAMPAIGN CLAIMS

JOBS

REMAIN Leaving the European Union would cause a ‘serious shock’ to the UK economy that could lead to 950,000 job losses, according to a report commissioned by the CBI.

LEAVE ‘If we vote Leave and are liberated from the shackles of EU membership, jobs will be safer, Britain will be able to spend our money on our priorities and we can look forward to faster growth and greater prosperity.’ said John Longworth, former director general of the British Chambers of Commerce.

POUNDS IN YOUR POCKET

REMAIN Asked if he thought the cost of mortgages would increase if Britain exited from the EU, George Osborne responded: ‘The short answer is yes. I think that is likely, but I’m not in charge of interest rates.’

LEAVE Tory MP John Redwood said: ‘It means higher wages as we cut the flows of EU migrants into low-paid jobs.’ He added: ‘Brexit means setting the taxes we want to impose. It means we can keep the corporate taxes we raise from big business, instead of losing £7bn every five years from European Court judgments making us send money back to those rich companies. It means we can abolish VAT on domestic fuel to tackle fuel poverty, scrap the hated tampon tax and take VAT off green products and insulation materials.’

NHS

REMAIN Health secretary Jeremy Hunt said: ‘The impact of an exit could cost the UK more than 5% of the size of our economy. This would inevitably mean less money for public services like the NHS.’

LEAVE Matthew Elliott, the chief executive of Vote Leave, said: ‘The NHS has plummeted into a financial crisis. If we vote to leave, we can stop wasting money on EU bureaucrats and instead spend our money on our priorities, like the NHS.’

IMMIGRATION

REMAIN ‘While there would be political pressure to reduce immigration following Brexit, there are several reasons why we believe headline net immigration is unlikely to reduce much,’ thinktank Open Europe reported.

LEAVE Former welfare secretary Iain Duncan Smith said: ‘Governments are elected on promises to cut the numbers arriving, but how can they do that when we have to accept unrestricted freedom of movement from Europe?’

SECURITY

REMAIN ‘Europe today is facing a series of grave security challenges, from instability in the Middle East and the rise of Daesh, to resurgent Russian nationalism and aggression. Britain will have to confront these challenges whether inside or outside the EU. But within the EU, we are stronger,’ wrote the former chiefs of defence staff field marshals Lord Bramall and Lord Guthrie, air chief marshal Lord Stirrup, admiral of the fleet Lord Boyce and general Sir Michael Rose, former special forces chief.

LEAVE Duncan Smith claimed being a member of the EU ‘leaves the door open’ to attacks such as those in Paris last year. The former welfare secretary said: ‘This open border does not allow us to check and control people that may come and spend time.’

INFLUENCE

REMAIN ‘The UK has exercised an outsize influence in the world for several centuries …we think that in today’s world, that kind of influence is best exercised through clubs,’ said Obama assistant Charles Kupchan.

LEAVE Iceland’s former prime minister, Sigmundur Gunnlaugsson, claimed that the UK wields ‘diminishing power’ in the EU. ‘When it comes to the big stuff, the decisions are made by two, and increasingly one, country,’ he said.