PUBLIC services union PCS announced legal action against the government’s minimum services levels legislation at the TUC’s historic Right To Strike rally this weekend.

The union’s general secretary Mark Serwotka made the announcement before thousands of trade unionists who gathered in Cheltenham for the 40th anniversary of the Tory ban on GCHQ workers joining a union.

In his last major speech before handing over the reins to Fran Heathcote, he said: “Here we are 40 years on and the Tories are trying to make it illegal for public-sector workers and others to take strike action in defence of their own living standards.

“I can announce today as the general secretary of PCS that we are launching legal action against the government, to stop this legislation stopping workers going on strike.”

Speeches by TUC general secretary Paul Nowak and other general secretaries followed.

Surviving members and relatives of the GCHQ campaigners who got Labour to repeal the ban in 1997 then got on stage to conclude the rally, thanking the trade union movement for its support.

Mr Nowak said: “After 13 long years they won back their right to union recognition and that tells me one thing and it’s a message to this government with their attack to the right to strike: the trade union movement has beaten you once and we will beat you again.

“Our whole movement will stand behind PCS’s action against the government.”

Unite general secretary Sharon Graham labelled the Conservative government the “real threat to national security” in a reference to Margaret Thatcher’s attack on the GCHQ workers.

She added: “As for Labour, this legislation must be removed, not in the first 100 days but in the first day of a Labour government.”

Unison general secretary Christina McAnea said: “It’s an absolute disgrace and an insult what happened here 40 years ago: this idea that you cannot be a trade unionist and be loyal to this country.”

Matt Wrack, TUC president and general secretary of the Fire Brigades Union which led the march with a fire engine, said it will hold Labour to account on its vow to repeal the minimum service levels laws that force striking workers to return to work.

He said: “We don’t rely on politicians, we rely on ourselves, working together in the workplaces through our unions.”

Communication Workers Union general secretary Dave Ward added: “It’s not just about getting them elected, it’s about getting them to change things for working people.”