There was a moment, an hour before Jeremy Corbyn took to the stage at the Labour Live festival, when he might have believed himself a rock star. The Labour leader, in his short sleeved linen shirt and his pale chinos, checking his pockets for his speech and his reading specs, was shuffled through the crowd by three burly security guards, barking into walkie talkies. The crowd duly parted, before chasing him en masse the few yards across White Hart Lane Park as he was bustled backstage. Three teenage girls started scrolling, screaming, to see if they had caught the great man doing his trademark pop-eyed grin on their selfies.

Jeremy Corbyn walks through the crowd before appearing on the main stage at Labour Live. Photograph: Chris J Ratcliffe/Getty Images

This is presumably the kind of excitement that the Labour organisers had envisaged when they promoted #Jezfest as an alternative Glastonbury. You would think after the party’s history with such jamborees – that takes in Kinnock’s Sheffield Rally, and the Millennium Eve fiasco in the Dome – that they might have learned to keep well clear of any event involving wristbands. For much of the day yesterday, they might have been wishing they had.

When the gates opened at noon there was no festival stampede toward the main stage mosh pit, rather a steady stroll, followed by a laying out of tartan picnic rugs and folding camping chairs. In this, it seemed that the event had something of the authentic character of its headline act, even if that actually made it more village fete than Sandinista rally. One of the obvious problems of performing under the slogan of “For the Many” is when only a few of them turn up.

Labour party supporters join in the festivities at Labour Live. Photograph: Andy Hall/The Observer

After a week in which Labour seems to have lost momentum in the polls – despite the tragic ineptitude of the government – and in which 90 of its MPs had defied the whip over Brexit, the leadership clearly wanted to avoid a damp squib of a summer festival at all costs. Labour Live was conceived as a vehicle to channel the great surge of youth support that Jeremy Corbyn in particular enjoyed around last year’s general election. The lack of enthusiasm that had very publicly dogged this event, ever since it was announced must have left organisers praying for rain, so at least they could blame the weather.

As it was, the sun mostly shone on the three very large tents and the main stage and on the queue forming outside the Unite the Union ice cream van that was giving out free 99s and playing a hurdy-gurdy version of the Red Flag. There was no visible revolt over the fact that half the crowd had coughed up £35 for their entry and the other half had been bussed in for free after the Labour party started desperately giving out tickets to make up the numbers. The growing sense that the leadership should not be reliably left in charge of party organisation at a brewery was compounded by the fact that the Workers Beer Company refused to provide keg versions of its product, because they were “reserved for high-volume events”.

Using the Sean Spicer method of calculation, by early afternoon the park was filled as far as the eye could see: there were probably 3,000 people enjoying the afternoon events that included a People’s Question Time with Len McCluskey (a prelude to his hosting of hip-hop karaoke at tea time). Tottenham’s local MP David Lammy did his best as a warm-up man for a muted crowd. Speaking to him afterwards he suggested that his experience of festivals was that it would only “really get going later”. “I didn’t have the best slot of the day,” he suggested, loyally, “that is for Jeremy and Clean Bandit”.

In The World Transformed tent activists were reaching out to a reluctant few dozen people on benches by trying to involve them in a game of “socialist runaround”. First question: “Jeremy Hunt is rhyming slang, agree or disagree?” Second question: “Will Labour take us back to the 1970s?” (This one came with a supplementary – “and would that be a bad thing?”) Final question: “Should we allow shareholders to make a profit?” Runaround now!

More of the crowd flocked to the literary tent where there was a grown-up discussion of whether Corbyn’s socialism was a viable vision, led by the Guardian’s Gary Younge. For a festival that was promoting free debate, however, it was hard to avoid the sense that there were one or two clear limits.

Outside I met a few young representatives of For our Future’s Sake who were planning a “friendly protest” against the party’s refusal to have a proper debate on Brexit policy. They were planning to unfurl a pro-Remain banner when Corbyn took the stage, though they feared their banner might be confiscated by Momentum heavies.

When – after an introductory DJ set that included Prince’s I Wanna Be Your Lover – the leader appeared, the banner was raised, and the Remain group and their banner were quickly ushered out. This allowed the leader of the opposition to enthuse a by-now significantly larger crowd of the converted with impassioned pledges to renationalise “rail, mail and water”, build a million council homes and to “support everybody”, while fans chorused his “Ooh! Jeremy Corbyn” theme tune. Like any headliner worth his salt, he knows to stick to the hits.