Border personnel are set to begin a job action on Friday at 4 p.m. (EST) if no deal is reached by then, says the Public Service Alliance of Canada, which represents more than 9,000 union members who work for the Canada Border Services Agency and who have been without a contract for more than two years.

The two sides went into mediation on Monday. The union says key issues include pay parity with other law enforcement agencies, flexible telework and remote work options, pension benefits and stronger workplace protections.

The Treasury Board says 90% of front-line border officers are designated as essential, which means they can’t stop working during a strike.

However, union members could use work-to-rule, a tactic where employees do their jobs exactly as outlined in their contracts, which experts say can be an effective tactic to slow down crossings significantly without breaking the law.

The union says similar action three years ago “nearly brought commercial cross-border traffic to a standstill, causing major delays at airports and borders across the country.”