Unite union leader Len McCluskey told London’s largest May Day rally in years yesterday that a general strike may be the “only way” to save Britain. 

He was cheered by the 10,000 workers, students and pensioners who flooded Trafalgar Square for International Workers’ Day despite a ferocious downpour.

Mr McCluskey accused the Tory-led coalition of trying to “dismantle” public services built by working-class people since the end of World War II.

“The only way we can defend that is by uniting together, having the belief in our own values and using everything at our disposal — including a general strike,” he said.

“When working people are confident, then we can take back the power that rightly belongs to us.”

A sea of banners held aloft by members of the Rail, Maritime and Transport (RMT) union paid tribute to late general secretary Bob Crow on a day specially dedicated to him and veteran socialist Tony Benn, who passed away in the same week in March.

An RMT brass band had earlier proudly led the annual procession from Clerkenwell Green.

Members of the union flanked Mr Crow’s daughter Natasha Hoarau as she delivered a powerful speech echoing the no-nonsense style of her principled dad. 

She said: “It hasn’t been an easy time for our family but we’ve been comforted by the passion we see here.

“He was inspirational, courageous and pushed us all to find ourselves, to stand on our own two feet.”

His memory is there “when I need to find my inner strength,” said Ms Hoarau, who revealed her decision to stand for the No2EU — Yes to Workers Rights coalition in place of her dad at the European elections.

The voices of Bob Crow and Tony Benn were also heard at the May Day rally for one last time as footage of famous speeches was played to Trafalgar Square on massive screens. 

Their inspirational words gripped not only the thousands taking part in the rally but tourists flocking to the National Gallery, who stopped on its steps and watched in silence. 

The massive turnout in defiance of the weather was also a resounding answer to Tony Benn’s final call to make the day an “uprising against austerity.” 

His great friend and Labour MP Jeremy Corbyn remembered he had been a “teacher, an educator, an inspirational speaker and a leader.”

He said: “What we have left behind is the memory of a great man who had been to the top of the mountain, in every sense, but never forgot from where our movement came, never forgot how to inspire ordinary people.

“Let’s learn from Tony.”

TUC general secretary Frances O’Grady said unions “have to stop” gross inequality in Britain today. 

She said it is simply “wrong” that children queue at food banks while five families hoard the same wealth as that earned by the poorest 12 million.

“There are times when the only way you will win justice, the only way you will win for workers is if you take strike action,” she added.