His growing popularity comes amid concerted rightwing attacks.
Attended by up to 1,500 activists and supporters, the veteran socialist set out his progressive program, amid intensifying attacks from his Blairite opponents.
Upon entering the hall, the 66-year-old Islington MP seemed momentarily bewildered by the roars of support from those packed into North London’s Camden Centre.
Twitter users have taken to calling the atmosphere around Corbyn’s campaign #Corbynmania.
He used his speech to sketch out a Britain committed to nuclear disarmament, in which railways and utilities are renationalized and the National Health Service (NHS) is protected from the creep of privatization.
Corbyn said he wanted to see a “country that doesn’t thrive on inequality” and told those gathered they were part of a movement brought together “on the basis of hope, on the basis of determination and on the basis of democracy.”
“All over the country we are getting these huge gatherings of people,” he said.
“The young, the old, black and white and many people that haven’t been involved in politics before. Is it because they want to see something different in society? Real democracy.”
Corbyn, who over the weekend addressed packed venues in Liverpool, Coventry and Birmingham, used the platform to recall the history of earlier radical movements in Britain, invoking everyone from the Chartists to the mineworkers who opposed Margaret Thatcher.
With many hundreds of supporters unable to access the main venue, Corbyn moved outside to the roof of a fire engine brought by the Fire Brigades Union (FBU) and addressed the crowd from there.
Tension is rising between the Corbyn and New Labour camps. The unpicking of Corbyn’s economic ideas, now touted as ‘Corbynomics,’ has become the latest weapon in that confrontation.
Shadow Chancellor Chris Leslie coined the term on Monday, telling the Daily Mail he would not serve in a Corbyn cabinet if the socialist won the leadership.
He said Corbynomics were too “starry eyed” and “hard Left” to work.
“You have got to have a credible Labour prime minister who understands this,” he said. “Otherwise you have a decade or more of Tory rule.”
His intervention comes amid claims by some Labour analysts that Corbyn’s economic plan could cost as much as £55 billion to enact. One of the architects of Corbyn’s fiscal plan was quick to fire back.
Tax expert and author Richard Murphy blasted Labour’s past economic antics, telling the BBC on Monday: “[Leslie] should remember that it was a Labour government that in 2009 created a program of QE [quantitative easing] that eventually printed £375 billion to bail out the banks.
“It didn’t work. It simply boosted bank bonuses and bank profits and ordinary people didn’t benefit.”
Activists have also defended the Islington politician’s plans, with YouTube star Artist Taxi Driver laying into Leslie over his comments.
He said Corbyn is “like a wave” ushering in “our moment in history.”