Travellers using Australia's international airports faced delays on Monday and were warned of more to come as immigration and border force workers went on strike over pay and conditions.
Morning peak-hour travel was held up with long queues forming in Sydney, which along with airports in Perth, Melbourne, Brisbane, Adelaide, Darwin, Coolangatta and Cairns experienced two-hour stoppages when staff walked out.
"These workers are angry, they're under pressure, they face major cuts to their take-home pay and workplace rights and government simply hasn't listened," said Nadine Flood, secretary of the Community and Public Sector Union (CPSU) representing workers.
The strikes affecting those departing and arriving on international flights are set to continue until September 30.
"Border Force workers feel they have no choice but to act, so they are prepared to strike every day, twice a day over peak periods, over 10 days," Flood said.
The union claims the government wants to reduce rights, conditions and allowances, cutting current annual pay for many staff by Aus$8,000 (US$5,735) and have called on new Prime Minister Malcolm Turnbull to resolve the 18-month dispute.
The Australian Border Force said passengers travelling in and out of the country over the coming week may experience delays at international airports due to the industrial action.
"Arrangements are in place to protect Australia's borders and minimise the impact on our operations, but if you are going overseas, we advise you to arrive at the airport early," it said in a statement.
Managers stepped in during the strike at Sydney Airport on Monday, but there were still delays.
"We've been about an hour and a half to get through; it's a bit chaotic in there to say the least," one traveller told the Australian Broadcasting Corporation.