Leaders of the biggest local government workers' union have rejected a two-year pay offer and will now consult members on the next step.
Unison officials narrowly voted against a proposed deal of a 2% rise for most council and support staff in England, Wales and Northern Ireland from April and a further 2% in April 2019.
Lower paid staff were offered a higher wage rise of up to 16% over the two years
Unison's head of local government, Heather Wakefield, said: "Unison's national joint council committee has today voted narrowly to reject the local government employers' two-year pay offer for council and school support staff.
"The union will now begin to consult with its members across local government in England, Wales and Northern Ireland to seek their views. That consultation will begin on Monday and end on March 8."
Unite is recommending rejection of the offer.