Jeremy Corbyn has hailed the Labour Live festival a success as he addressed supporters at the London event.
The one-day showcase of politics, music and arts had been hit by reports of sluggish ticket sales but the party insisted that more than 13,000 were bought ahead of the gathering.
Chart-toppers Clean Bandit provided the musical headline act for the event which was dubbed "Jez Fest".
Other events at the festival included a performance by former Sex Pistol Glen Matlock and a World Cup-themed discussion on "socialism and football".
Many attendees sported "Bollocks to Brexit" stickers despite the Labour leader's insistence the party respects the outcome of the EU referendum.
Talk of poor turn-out led Prime Minister Theresa May to ridicule the festival in the Commons.
However, Labour insisted it was a success, with a spokeswoman saying: "The tents have been packed all day. This is the first event of its kind organised by a political party and we have demonstrated how politics can be opened up to a wider audience and to people who have been shut out for far too long."
Concerns that the party could be embarrassed by low turn-out saw ticket prices slashed from £35 to £10 in recent weeks.
When the Labour leader took to the stage, supporters chanted the now familiar "Oh, Jeremy Corbyn" to the tune of Seven Nation Army by the White Stripes.
Mr Corbyn congratulated attendees on the party's showing in last year's election, stating: "My only sadness is that we didn't quite win that election."
The Labour leader branded the Tories "the party of the rich for the rich".
Mr Corbyn said his message for the Tories was: "You crept back into office a year ago. You started bunging money around in order to stay in office.
"For goodness sake, give up, move on, move over and let the people take over."