NURSES, teachers and firefighters could be out of a job if David Cameron keeps his, TUC assistant general secretary Paul Nowak will warn today.

Mr Nowak will use his speech at London’s May Day rally to brace workers for another public-sector jobs cull if the Tory Prime Minister remains in power.

The Conservatives have slashed 140,000 public-sector jobs in the last year alone — leaving employment in the sector at its lowest this millennium.

But billions more in planned cuts mean that “hundreds of thousands” more public servants would lose their jobs over the next parliament.

And he will warn that their plans to impose a “punitive” 50 per cent turnout threshold on strike ballots will tie the hands of threatened workers.

“No democracy elsewhere in the world has this kind of restriction on industrial action,” he is expected to say.

“It is a democratic outrage, especially as the Conservatives have opposed allowing secure and secret online balloting — the one measure guaranteed to increase turnouts.

“The Conservatives plan on making hundreds of thousands of public-sector workers redundant over the next parliament and want to make it impossible for them to fight back.”

Mr Nowak makes the warning as workers across the world celebrate International Workers’ Day.

He will be joined at the London rally by the leaders of unions who represent the public-sector workers at risk under another Tory term.

Fire Brigades Union leader Matt Wrack, civil servants’ union PCS general secretary Mark Serwotka and former dinner lady and GMB president Mary Turner will also address the crowds.

Around 5,000 workers are expected to march through central London behind their union banners before taking over Trafalgar Square.

Workers from the National Gallery, who are on strike over plans to outsource 400 security and visitor services jobs, will be among them.

Today’s rally for workers’ rights comes just six days before the election, which Mr Nowak believes is the “most important in our lifetime.”

The TUC deputy leader describes it as an “election that will shape the kind of country we live in for a generation to come.”

Rallying workers to get out and vote, he will say: “Britain is crying out for change and we need stronger unions to help deliver it.”

Plaid Cymru leader Leanne Wood said yesterday it had been her party which had been “at the forefront of championing the rights of working people during this election campaign.”

“I urge all those who share vision of fair pay and conditions, to give their support to us on election day so we have a mandate to deliver,” she said in her May Day message.

But Unite leader Len McCluskey urged trade unionists not to “gamble” at the polls in an article for Labour List.

He wrote: “If you want to get rid of the Tories from No 10 then the only way to do this is to vote Labour.

“This is a class issue and millions need to be united so that we can turn back the tide of austerity and the attacks on our communities.”