FRANCIS O’Grady, the TUC General Secretary, is urging Theresa May to “get on with it” and tell Chancellor Philip Hammond to scrap the one per cent pay cap for millions of public sector workers.

Addressing the annual Congress in Brighton today, Ms O’Grady will say in her keynote speech: "The Prime Minister talks about the 'sacrifice' public sector workers have made, as if it were their choice; public servants weren’t given a say in the matter. They’ve had seven years of pay freezes and pay cuts imposed upon them.

“They have been forced to work harder for less, while the Government has lined the pockets of corporate Britain with tax giveaway after tax giveaway.”

She will add: “On October 17, public servants will rally on Parliament Square and send a clear message to Mrs May: five million hardworking public servants need a pay rise. The public backs it. Now just tell the Treasury to get on with it.”

First Minister Nicola Sturgeon has already pledged to scrap the one per cent pay cap for public sector workers in Scotland and, after a raft of UK Government ministers came out in support for lifting the cap south of the border, Mr Hammond is expected to make an announcement towards this end in his Autumn Budget. Speculation is rife that the first move will be to trigger a pay rise for the police in England and Wales.

Meanwhile, Unison, the public service union, announced it was targeting Tory MPs in marginal seats in its bid to get the pay cap lifted.

Union members in 27 constituencies with small Conservative majorities are being urged to press their MP to support ending the one per cent limit.

Labour announced yesterday that it would lead a debate and force a vote on public sector pay in the Commons on Wednesday.

Union leaders attending the Congress said all public sector workers deserved a decent wage rise as they stepped up campaigns with warnings of co-ordinated industrial action.

Dave Prentis, Unison’s General Secretary, said: "All public service workers have suffered from the austerity agenda. It is not just an issue for the police."

He said it would be "disastrous" for public services if some groups of workers were given rises at the expense of others.