Over 250,000 members of the PCS civil service workers' union are taking part in a consultative ballot to decide the next step in their dispute over job cuts, low pay and privatisation.
Workers have struck solidly twice this year. Last week the Defra department announced 20 compulsory redundancies in its Wildlife Administration Unit.
Compulsory redundancy notices have been issued to staff working for the unit in Polwhele and Aston Down. Some of them are working on secondment in Animal Health as they struggle to contain foot and mouth and Bluetongue disease.
Many PCS members want the union to take joint action with other workers in dispute over pay, such as the Unison union members in local government who are balloting over pay. The ballot ends on 22 October.