Australian Border Force (ABF) management is threatening to send staff home without pay tomorrow, in what unions describe as a "nasty" move in an escalating industrial fight.

More than 500 ABF officers at ports, air freight terminals and mail centres were going to take part in "limited work bans" over pay and conditions, according to their union.

But the Immigration Department will not pay staff that engage in the action, regardless of its length or duties they perform over the rest of the day.

The Community and Public Sector Union (CPSU) said the department was trying to intimidate workers whose limited stop-work is protected by the Fair Work Commission.

"Members were already outraged that the Government's bargaining policy was putting many of their conditions and rights at risk, with many staff facing cuts to their take-home pay of $8,000 a year or more," CPSU secretary Nadine Flood said in a statement.

"The department's latest move has now added insult to injury ahead of the 24-hour strike by all Immigration and Border Protection staff on Monday."

The full-day strike by ABF staff next week could cause major delays for travellers.

Frontline workers at eight Australian international airports will participate, potentially slowing passport and arrival card checks and delaying baggage and cargo.

The Immigration Department has been contacted for comment.