Teachers, firefighters and council workers from across Wiltshire will meet at County Hall tomorrow as part of a coordinated day of strike action.
The Unison union has organised a rally in Trowbridge at 10.30am, where they will be joined by members of the GMB, PCS and Unite to protest over pay offers.
Sue Anderson, Wiltshire Unison branch secretary, said: “Our members are finding it difficult to manage personal finances and many are struggling to survive.
“It is never easy for members to take strike action, and it is always a last resort, but they feel very strongly about this and we are expecting a good turnout at the rally.”
Members of the National Union of Teachers will also be striking over pay and workloads, with high schools across the county expecting to be disrupted.
The Corsham School will only be open to sixth form students, while Devizes School and Hardenhuish School will only be partially open.
Malmesbury School will be open as normal, but students are warned to expect disruption to planned lessons. All other north Wiltshire schools are due to open as usual.
Members of the Fire Brigades Union will also join fellow public sector workers at the rally, with fire stations in Chippenham, Pewsey and Calne expected to close.
Wiltshire Fire and Rescue Service has contingency plans in place to cover any emergencies.