Unison, the GMB and Unite said they wanted the rise to cover one year from April despite attempts by the Prime Minister Gordon Brown to agree three-year pay deals in the public sector.

The claim would give a minimum wage of £6.50 an hour for local government workers in England, Wales and Northern Ireland.

Unions said it was a "catch up and match up" claim to recoup losses from below-inflation pay awards since 2004 and to keep up with inflation over the coming year.

Unison national officer Heather Wakefield said: "Despite the headline figure, this is a modest claim. No one could argue that an increase of 50p an hour fuels inflation.

"Over the past three years local government workers' pay has increased by less than the rate of inflation, so we are starting from a low base. We need to make sure that they catch up with the rest of the public sector and that they are cushioned against inflation over the coming year.

"The Government's 2% limit is just not on. It is half the rate of inflation and represents a real pay cut for loyal, hard-working public sector workers, two-thirds of whom are women. They are struggling to make ends meet with the ever-increasing spiral of housing and fuel price rises."

The claim covers all grades of workers in local government, including refuse collectors, school meals, social workers, administrators, cleaners, teaching assistants, parks and leisure, and librarians.

Unions representing millions of public sector workers were also urged to take joint action over pay in the face of attempts by the Government to strike three-year deals.

The Public and Commercial Services union said it feared the longer deals will lead to below-inflation settlements for civil servants, council and NHS workers and other public servants.