International passengers may face significant delays at airports in Australia as customs staff will go on strike around the country on Thursday to protest stalled pay negotiations with the federal government, the Community and Public Sector Union (CPSU) said on Wednesday. Customs staff at Sydney, Melbourne and Perth international airports will walk off the job for 24 hours from midnight on Wednesday, the CPSU said in a statement. Customs staff at Brisbane, Darwin and Adelaide international airports will strike for two hours on Thursday. Industrial action is also planned at Cairns and the Gold Coast international airports on Thursday. \"What we may see, particularly at Sydney, Melbourne and Perth international airports, is some significant delays for some inbound international passengers,\" CPSU National Secretary Nadine Flood said on Wednesday. \"The purpose of this action is not to inconvenience passengers, it is to send a very clear message to customs management and the federal government that it\'s time to resolve these issues.\"