Being on the winning side has left Edmund Kelly, a long-time activist from Reading, feeling a little disconcerted. His reaction on hearing it confirmed that Jeremy Corbyn won by a landslide was "euphoria", followed instantly by unease. That's what decades of losing does to you, Kelly says, as he stands in the sunshine outside the Queen Elizabeth conference centre, waiting for the new Labour Party leader to emerge.
“I’ve been a socialist for 30 years. We have always lost,” he says. “But I don’t yet feel like I’m on the winning side. I feel like now we’ve got a battle.”
His chief concern is the pressure Corbyn could come under from within. Most Labour MPs opposed the veteran left-winger, and Kelly fears the incoming leader may be nudged away from his core policy positions. The scale of the Islington North MP's triumph gives him a strong mandate, however, and Kelly says he can't wait to see the new leader confront David Cameron across the floor of the House of Commons each week.
As supporters waited for the victorious Corbyn to emerge (he ended up slipping out a side door, perhaps to avoid the press), the scene was one of celebration, delight and – for all the opinion polls that gave them hope in recent weeks – barely concealed shock.
Nicky Adams, a community worker who joined a trade union so she could vote for Corbyn as an affiliated member, says she is "astonished" he won.
“I’m absolutely thrilled,” she says. “We feel like our time has come at long last. All those people that opposed the Iraq war, opposed austerity, that never had a voice, this is our chance. We’re determined to stay together, keep the momentum going.”
Around us, chants rise from the crowd. "The people, united, will never be defeated," shouts a group of Corbyn supporters. When former mayor of London Ken Livingstone arrives, they go wild. "Ken, Ken, Ken!"
Adams says two issues were particularly important to her: decriminalising sex work, and humane treatment of asylum seekers. On both Corbyn was “solid”. But her attachment to his platform goes further.
“I’m always going to know that how I felt all those years, when I saw nothing representing me in parliament, loads of other people felt like me. You can’t take that away from people.
“You feel like one of many, and that feels like massive encouragement . . . I think things have really changed fundamentally.”
For Luis Rivas, who works in health administration in London, Corbyn's appeal was his apparent sincerity and ordinariness. "While other politicians are sitting in their nice comfy seats in parliament, he's out there supporting just causes – hospitals getting shut and things like that. I've seen him at many rallies and protests," Rivas says. "He has convictions and beliefs. The main thing is that he's one of us."
Critics of the 66-year-old see him as an unelectable liability who will struggle to reach beyond the left and win support in the middle ground, where elections are won and lost. Corbyn’s supporters see it differently, arguing his success could revise basic assumptions about the electorate.
“This country has become effectively a one-party system. Blair’s Labour is almost like a pseudo-Tory party,” says Rivas. “How do we know that all those people who don’t vote don’t vote because they are disillusioned with the Labour Party?”
Nicky Adams, wearing a red Corbyn sticker on her forehead, says the result marks the end of Blairism, leaving its centrist programme “dead and buried” as a political project.
“I think the Tories are going to get a big run for their money, because now, what Jeremy Corbyn’s campaign showed is that there is a massive groundswell of people who do feel strongly about a whole set of crucial issues, starting with austerity and resentment that people are being made to pay for a crisis that was not of our making.”
For Labour's centrists, Saturday's result was a painful defeat. Mike Harris, a Labour councillor from Lewisham in southeast London, says he feels "totally dejected" by Corbyn's victory and sees it has having fundamentally changed the party he joined.
"A number of people, myself included, have gone from being where the political centre of the party was to being marginalised figures," says Harris, who supported Liz Kendall in the leadership election.
He says the scale of Corbyn’s win will make it “extremely difficult” for Labour moderates to “have any legitimacy in pushing back against Corbyn”.
And yet he cannot imagine the veteran MP will still be Labour leader in 2020.
“It’s impossible to conceive that Jeremy Corbyn will be put in front of the British electorate in 2020 and that we’ll be saying: this should be your prime minister.”