Staff are calling for a 5% pay rise or£500, whichever is greater, and will start bargaining with employers early next month.
In a joint 'warning' statement, lead negotiators from Unison, the GMB and T&G this week said their members expected a reasonable deal and would not accept the costs of implementing single status as a factor in reducing the settlement.
Unison deputy head of local government Virginia Branney said workers had received a below-inflation increase last year, while private sector earnings were 'racing ahead'.
In some cases, councils were overstating the costs of single status to reduce pay expectations, she said.
'Employers are going into talks based on the worst-case scenario as their opening gambit,' she said, 'but in serious negotiations those costings are being unpicked and reduced.'
Ms Branney warned that industrial action was 'not being ruled out' and added: 'There is a very different mood among local government staff than at this time last year.'
T&G national secretary Jack Dromey said the 'most generous [local government finance] settlement in years' from central government had raised members' expectations.
GMB national secretary Mick Graham said more than half a million council workers were still defined as low-paid, despite increased hourly rates.
Employers finish consulting with councils on the pay deal on 25 January.