Leaders of 1.6 million council workers have submitted a claim for a "substantial" pay rise, arguing that a freeze on their wages has gone on long enough.
Unions said care workers, librarians, school dinner ladies, teaching assistants, refuse collectors and street cleaners were among employees who have been hit hard by the three-year pay clampdown.
The GMB, Unison and Unite, said local government workers across England, Wales and Northern Ireland had seen their pay fall by 13% in real terms because of the freeze on increases.
Brian Strutton, national officer of the GMB, said: "Our claim for a substantial pay rise from April 2013 and progress towards a living wage is submitted before councils set their budgets for next year in the expectation that we will break the pay freeze that has been imposed since 2010.
"Over that time staff have faced the double whammy of a 13% real terms pay cut and 200,000 job losses, showing that pay restraint doesn't necessarily protect jobs. As a result local government pay starts at just £6.30 an hour, only 11p above the national minimum wage and hundreds of thousands of council staff are relying on state benefits to make ends meet.
"Council leaders have already said they are preparing to make an offer to raise pay but at the expense of worsening terms and conditions. There is little to commend this 'give with one hand and take with the other' approach and I predict a rocky road ahead for these crucial negotiations."
Unison's head of local government, Heather Wakefield, said: "The Government's cruel and relentless austerity agenda has gone far enough, and it is time for the assault on the wages of local government workers to come to an end.
"With this pay claim, our position is clear - it is high time for fair pay and that means a substantial increase."
Unite national officer Peter Allenson said, "It is clear that many local authority employers have lost their moral compass by tugging their forelock to this austerity-obsessed Government. Council workers have seen their take home pay slashed by 13% since 2009, while household bills have soared.
"Three years of pay freezes have been compounded by some authorities not even paying the £250 due to those earning below £21,000. Those employers have even out-Scrooged George Osborne, which is quite a feat."