Local government employers have been accused of denying a pay rise for 1.6 million council workers after an expected offer failed to materialise.
Unions representing staff ranging from refuse collectors and school cleaners to architects and social workers across Wales, England and Northern Ireland made a claim for a £1.20 an hour wage rise.
The two sides were due to meet today but unions said they have been told an offer will not be made until the Government announces the new rate for the national minimum wage in May.
Heather Wakefield, national officer of Unison, said: "The employers' attitude to our members providing vital local services and supporting children in schools has reached an all-time low.
"Using the national minimum wage as an explicit benchmark for our members' pay for the first time ever shows just how little the employers and the Government value their amazing contribution to local communities and children in schools. It also shows their disdain for women workers who make up more than three-quarters of the workforce.
"School support staff, library assistants, care workers, clerical assistants and cleaners now find themselves regarded as the lowest skilled and lowest valued in the labour market. It's a shameful culmination of years of neglect of workers who keep our communities clean and safe, care for our elderly and help our children learn.
"This shoddy treatment has to end once and for all. The Government needs to put its money where its mouth is, end low pay in schools and councils and stop the unnecessary cuts to council funding."
Unions said council workers' pay has fallen by 18% in real terms since the coalition took office in 2010.