Sweeping job action by Canada Border Services Agency employees beginning today.
Close to 9,000 members are taking work-to-rule action to back demands for a new contract.
The unions representing the workers served strike notice to the federal government earlier this week.
They warn that travellers should expect long lineups and lengthy delays at border crossings and airports.
Employees want better protections against what they describe as toxic workplace culture and greater parity with other law enforcement agencies.
They have been without a contract for more than three years.
Contract talks are expected to resume today.
The sweeping job action comes just days before the Canadian border is to reopen to fully vaccinated U.S. citizens on Monday.
