Friends House in central London was full to capacity on Thursday night for the opening rally of this year's Marxism festival.
Maria Styllou from SEK, the Socialist Workers Party's sister organisation in Greece, opened with a gripping account of the tumultuous struggles in Greece over the past year.
She spoke of the growing polarisation between a ruling class intent on forcing through austerity measures and a rising left wing movement linked to working class struggle.
'We need to build in workplaces, build an anti-fascist base—and build the anti-capitalist and revolutionary left,' she added.
Rank and file electrician Ian Bradley spoke about their successful campaign earlier this year to stop construction firms from ripping up terms and conditions on building sites.
Socialists had played a vital role in this struggle, he said. 'It was socialists who argued for unity when bosses tried to use racism to divide us—and helped make sure we didn't go down the road of 'British jobs for British workers'.
'It was socialists who had the politics to work with the union when it was doing what we wanted but outside it when it wasn't.
'And it was socialists who brought in solidarity that made us feel part of a bigger struggle. That's why I'm proud of the role I played as a socialist and a member of the SWP.'
SWP industrial organiser Martin Smith ended the rally with a call to gear up for a 'hot autumn' of struggle involving the 20 October TUC anti-cuts demo, the 21 November student demonstration and strikes by teachers, civil service workers and transport workers.
These events would fuse together struggles that had previously tended to remained separate. 'We can shut this country down—and we can shut Cameron up,' he said.
But Martin warned that the events of last year showed that while left wing union leaders could pull right wing ones into struggle, the pressure could also be applied the other way round to dampen down industrial action.
'That's why we need to build a strong rank and file workers' movement that can organise independently of the union leaders,' he said.
Other speakers included UCU executive member and LGBT activist Laura Miles who talked about the need to put the politics and protest back into Saturday's World Pride, and newly re-elected socialist councillor Michael Lavalette.
Some 4,500 tickets have already been sold for Marxism 2012 making it the biggest Marxism festival in over a decade.
Highlights tomorrow (Friday) include Gary Younge speaking on politics and protest in the US and Egyptian revolutionary Gigi Ibrahim on youth, rage and revolution.