The bar at York racecourse was doing a lively trade as a crowd of a couple of a hundred, most of them men, many in Vote Leave T-shirts, sank a few pints as they waited for Boris Johnson. It was a nice, cold, sunny English evening – "barbecue weather, we call that in Yorkshire" – and the mood was festive as we waited for the show to start.

Outside, a small group of dissenters were dressed as bananas, in mockery of Johnson's recent claim that an EU directive limited the size of a bunch of bananas and banned those with the wrong curvature.

The former London mayor is the undisputed star of the Leave campaign, one of the few politicians in England voters will cross the street to greet, and his campaign stops draw big crowds and national media coverage. He had spent the afternoon driving a sports car around in circles at a factory in Leeds and dismissing as propaganda the latest treasury warning about the economic cost of leaving the EU.

Immigration

A group of young supporters were lined up onstage, holding Vote Leave signs in front of a banner saying “let’s take back control”, as the warm-up speakers began. First up was a young doctor who spoke about the burden immigration from the EU was placing on the National Health Service.

Then came a young Sikh woman with a punchy denunciation of the EU and a defence of the British values embraced by her immigrant forbears. Her speech went down well, although her complaint about restrictions on religious headwear and other symbols in French public buildings may not have resonated with the entire audience.

And suddenly, there he was, his face a delicate shade of pink, his golden thatch gently ruffled, his suit crumpled and shoes scuffed as he clutched some notes and a folded newspaper. It was, Johnson told the crowd, appropriate that they were meeting at a racecourse.

“We are in the final furlong of this historic referendum campaign and it is in the final furlong that the horses change places, don’t they? Let’s win that referendum on June 23rd. Can we win it? I think we can,” he bellowed.

‘Highway robbery’

After a brief discursion comparing

Dick Turpin

, who was hanged nearby, to the EU – “the people of York decided that they’d had enough of highway robbery” – he addressed the banana controversy head on. “I looked it up and I’m afraid I was wrong. There isn’t just one directive on bananas. There are four directives on bananas,” he said. “Do you think we need the

European Union

to tell us how powerful our domestic appliances can be? Do we need Brussels to tell us how much suction power our vacuum cleaners need?

“I’m prepared to accept that a vacuum cleaner, if incautiously used, may lead to some people doing themselves an injury. But we have plenty of officials in this country who have concentrated their minds on the safety of electrical appliances. Do we need Brussels to tell us how powerful our hairdryers ought to be or how long we have to wait until our toast is brown?”

This is good, old-fashioned populist nonsense of the kind Johnson pumped out every day when he was the Daily Telegraph's Brussels correspondent 20 years ago and the audience loves it.

"Write the menu now, Boris, and we'll all enjoy a full English Brexit, " one man roars.

They cheer when he dismisses David Cameron’s renegotiation deal as “frail and worthless” and denounces the “negative spirits” warning of the dangers of leaving the EU.

Call and response

Johnson’s speaking style is unique, partly relying on a kind of music hall call and response of rhetorical questions, his language a Wodehousian amalgam of the demotic and the lyrical or absurd that keeps everyone guessing.

"This is a huge struggle that we've now got on. It is us, the few against the many, it is us hardy little platoons against the big battalions of the CBI and Goldman Sachs and Peter Mandelson. All the people who were wrong in the past," he said.

"The difference between them and us is that we have the passion and the courage and the sense of duty to speak up, not just for the people in this country but I think for hundreds of millions of people across Europe who secretly or openly agree with us."

It was fighting talk but Johnson's side is looking increasingly like the losing side and a new poll by ORB for the Telegraph shows support for Leave collapsing among older voters, men and Conservative supporters. In these three key demographics, long the mainstay of the Leave campaign, majorities now want to remain in the EU.

Johnson's critics portray his support for Brexit as a cynical stratagem aimed at securing the leadership of the Conservative party after Cameron steps down. But his performances during the campaign have been erratic and undisciplined, his bluster over bananas and flimsy grasp of facts making him look anything but prime ministerial.

“Following a British vote to leave, there will be a mood of sudden excitement and euphoria in many parts of Europe because somebody will finally have told them that the emperor has got no clothes,” he told the crowd in York.

The question is, which emperor?