School and early years staff in 10 council areas will walk out on September 13 and 14 in a dispute over pay, a union has announced.

Essential staff in schools and early years will strike for two days next month, as the GMB union claimed low-paid Scots education workers were being offered a rise £700 less than their southern peers.

About a third of council areas will be impacted – with 10 local authorities being warned of industrial action from catering staff, janitors, cleaners and support workers.

The action comes after GMB Scotland’s members rejected the 5.5% offer from council umbrella body, the Convention of Scottish Local Authorities (Cosla), in April, branding it unacceptable amid surging inflation and the cost-of-living crisis.

The union, which represents more than 21,000 workers across 32 councils, claimed Cosla refused to revise the offer or ask the Scottish Government for support.

Staff will walk out on September 13 and 14 in Aberdeen, Clackmannanshire, Comhairle Nan Eilean Siar, Dundee, East Dunbartonshire, Falkirk, Glasgow, Orkney, Renfrewshire and South Ayrshire.

More strikes could occur across schools and early years in September with the members of another union already voting for industrial action while another is currently balloting members.

GMB Scotland said the Cosla offer would mean a rise for the lowest-paid workers in Scotland’s councils that is £700 less this year than that offered to colleagues in England and Wales.

Keir Greenaway, GMB Scotland senior organiser for public services, said a meeting on August 25 would be the final opportunity for Cosla to avert disruptive strikes.

Mr Greenaway said: “The latest figures show that, despite rising wages, pay is still being outstripped by inflation.

“The pay offer to council workers does not come close to matching the surging cost of living and one that is worth less with every month that passes.

“Scotland stands on the shoulders of our local authority workers and the value of their work must be reflected in their salaries.

“Cosla has refused to seriously engage with our members during what has been a protracted, frustrating process. If they had, parents and pupils would not now be facing disruption.

“Cosla and Scottish ministers need to engage now or risk turning a crisis into a calamity.”

A Cosla spokesperson said: “The reality of the situation is that as employers, council leaders have made a strong offer to the workforce.

“A strong offer which clearly illustrates the value councils place on their workforce, and it compares well to other sectors.

“It recognises the cost-of-living pressures on our workforce and critically, it seeks to protect jobs and services.

“While the offer value in year is 5.5%, the average uplift on salaries going into the next financial year is 7%.

“Those on the Scottish local government living wage would get 9.12% and those at higher grades, where councils are experiencing severe recruitment challenges, would see 6.05%.

“It is an offer which recognises both the vital role of the people who deliver our essential services across councils every day and the value that we, as employers, place on them.

“Crucially, it also raises the Scottish local government living wage by 99p to £11.84 per hour and sets out a commitment to work with our trade unions to develop a road map to £15 per hour in a way that protects our workforce and services we deliver.”

A Scottish Government spokesperson said: “Local government pay negotiations are a matter for local authorities as employers and unions.

“The Scottish Government and Cosla have committed to respect this negotiating arrangement as part of the Verity House Agreement.

“Despite UK Government cuts, the Scottish Government has provided a further £155 million to support a meaningful pay rise for local government workers, which has been taken into account in the pay offer already made by Cosla.

“The Scottish Government urges all the parties involved to work together constructively and reach an agreement which is fair for the workforce and affordable for employers.”