The trade union Unison will send ballots for strike action to 38,000 staff at schools and early years centres across Scotland.

Unison said staff could walk out in September if union members back strike action in a pay dispute with the local authority umbrella body, Cosla.

The ballot for school staff begins on July 18, while a separate ballot for Unison’s staff in waste and recycling services closes on July 17.

It comes after waste and refuse workers in 13 councils voted in favour of industrial action, as GMB Scotland members rejected the latest pay offer from Cosla.

Cosla’s two-stage offer lasting 18 months would see staff receive a 2.2% increase for the first six months of the deal and an extra 2% for the next 12 months.

Unison said staff should have a pay deal which compensates for previous below-inflation pay increases.

Unison Scotland local government committee chair Colette Hunter said: “Cosla’s lack of engagement on pay is bitterly disappointing.

“Local government workers firmly rejected Cosla’s offer in a consultation earlier in the year. There should have been talks way before now. It doesn’t show any great desire to resolve this dispute.

“Local government workers were due a pay rise at the beginning of April and are becoming increasingly disillusioned. They feel undervalued, and the delays will do nothing to fix the recruitment and retention issues we have within local government.”

Unison Scotland lead for local government, David O’Connor, said: “No one wants to take strike action. It’s always a last resort.

“Cosla’s proposal falls short of Unison’s pay claim. It’s also less than the offer made to the lowest-paid local government staff south of the border.

“Workers are simply asking for a pay deal that addresses below-inflation pay settlements, which have reduced the value of staff wages by a quarter over the past 14 years.

“Council workers deserve to be paid wages reflecting their essential roles.”

Cosla has been approached for comment.