International travellers could face delays at airports as Australian Border Force staff prepare to strike.
Workers will walk off the job at eight international airports and other sites for 24 hours next week in their ongoing campaign against the government on pay and conditions.
However, staff who choose to join the strike are being warned to not expect to get paid.
"We have taken the difficult decision to issue `no work no pay' notices to employees in Australia," the Department of Immigration said in a statement on Friday.
Only those employees who completed all their duties will be paid while others would have a full day's pay deducted, even if they only took part for a few hours.
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The department says cargo and mail could be affected in the lead-up to Christmas.
Unions said some staff will be excluded from walking off the job to protect national security.
CPSU national secretary Nadine Flood said talks with the government on pay and conditions have so far failed to produce a meaningful outcome.
