Rolling strike action by thousands of public servants will start today and expected to continue for up to four weeks slowing down visa processing and causing significant delays at airports.

The department of immigration has warned that Immigration staff and Border Force officers will stop work at various times at international airports, ports, container examination facilities, client services and visa processing sections and international mail facilities.

The strike action will start today at airports in Cairns, Townsville, Perth, Darwin and Adelaide before the major airports in Sydney, Melbourne, Brisbane and other locations join in on Thursday for a 24-hour strike.

The strike is a result of the failure in negotiations between the Community and Public Sector Union (CPSU) and the government over workplace agreements and pay of public servants, following the department's merger with Customs last year.

The department has warned that “delays will occur and those travelling overseas over the Easter period are encouraged to arrive early at the airport, and then to proceed directly to customs and immigration clearance. Travellers who have not yet booked their travel or who are able to reschedule to another day are encouraged to do so. The Department recognises this will cause inconvenience and have an impact on the travelling public.”