TAX workers will strike for a third time in a year next week.
Members of the Public and Commercial Services Union working at Revenue and Customs plan to walk out of work on Tuesday.
Revenue and Customs has one of its biggest bases in the country in Victoria Avenue, Southend.
The union is protesting against what it calls the "privatisation" of Customs contact centres.
Members also striked last year over changes to sick leave rules and contact centre closures.