TRADE union leaders made it clear that Saturday’s thousands-strong march was a dress rehearsal for planned strikes on July 10 that could see millions walk out.

Unite general secretary Len McCluskey pledged to rally his members for a “general strike when that is necessary.”

The National Union of Teachers (NUT) has already called action for July 10 against Tory Education Secretary Michael Gove’s pay and pensions raid, while Unison and GMB are tipped to bring their members out on the day.

Mr McCluskey received enthusiastic cheers when he pledged: “We will make certain that we use every tool at our disposal.”

The Unite leader said it was the values of those marching on the day that spoke for the millions living in poverty.

In contrast, he labelled the coalition a group of “posh boys.”

The People’s Assembly was able to galvanise those standing against the austerity agenda and the coalition government, he said.

Members of the NUT also came out in force for the march, with hundreds of teachers and their families, many in their green campaign T-shirts, forming a noisy block. 

General secretary Christine Blower said: “The reason why the People’s Assembly caught people’s imagination is because everybody knows that austerity is wrong.

“The poor, disabled, women with children are being left behind and cut adrift,” she said, while “the rich are getting richer.”

Those were the reasons the NUT is taking strike action on 10 July.

Many other unions were also present on the day, with public-sector union Unison, civil servants’ union PCS, transport workers’ union RMT, actors’ union Equity, and more displaying their banners, flags and balloons.

Some of Labour’s loudest voices for social justice — including Hackney North and Stoke Newington MP Diane Abbott and Islington North MP Jeremy Corbyn — also joined the march.