The Canada Border Services Agency is warning motorists to expect delays and lineups at the Emerson crossing on Thursday because of "work refusals by several officers at this port of entry."
Manitoba becomes the second province to see job action as a result of the policy.
The CBSA said the disruptions are because the unionized border officers are refusing to wear name tags — a new policy that went into effect on Tuesday.
The union representing the border agents argues that being forced to wear a name tag, with officers' last names displayed, potentially opens them up to retaliation from angry drivers.
The Public Service Alliance of Canada says there are approximately 70 border agents in Emerson, but it's not known how many of them are refusing to work on Thursday.
Marianne Hladun, the union's regional vice-president for the Prairies, says some of the officers don't feel safe having their last names on their name tags.
"There's no reason to put a name tag on an officer, which then puts not only them, but their families, at risk," she told CBC News.
Hladun said the officers already wear tags that show their five-digit identification numbers.
But the CBSA says wearing name tags does not pose a safety risk for officers. It points out that U.S. border and customs agents, Canadian Forces members and federal corrections officers all wear name tags.
"Personalized name tags reflect our commitment to service excellence and reinforce the professionalism and integrity for which CBSA officers are known," the agency stated in a release.
Border agents at two Ontario crossings — Windsor and Sarnia — walked off the job on Wednesday for the same reason. Travellers faced delays of up to two hours as a result.
The border agency said the officers at those two locations have since returned to work, wearing the name tags.