Guests at Victoria’s most well-known hotel could be crossing picket lines for the Labour Day long weekend.

The union representing about 500 workers at the Empress Hotel has served 72-hour strike notice over what it says is frustration with staffing levels.

Unifor Local 4726 says a strike could start and picket lines could go up as early as Thursday morning.

A national representative for Unifor said ongoing renovations at the hotel have posed health and safety risks for workers, while understaffing has forced others to work overtime.

It’s so bad some staff members have worked more than 60 consecutive days without a day off, according to Unifor.

The union said it wants to establish limits on overtime and have more control over what kind of work employees do.

"I'm confident we can work through our differences, but the owners have to show some appreciation to the workers who are making the Empress a successful business," Unifor National Represenative Stu Shields said in a statement.

Representatives for the Empress declined to comment on employees' concerns about staffing levels, saying collective bargaining is still underway.

"We are hopeful for a quick resolution. We pride ourselves in working as a team to provide outstanding service to our guests," Empress General Manager Indu Brar said in a statement.

Brar said the hotel's main goal is to continue bargaining with Unifor "in order to reach a mutually beneficial agreement."

Renovations have been underway at the century-old hotel for months, and the hotel recently shut down its iconic Bengal Lounge in favour of a modernized dining room.

The hotel was sold to developer Nat Bosa in 2014 for an undisclosed amount, but its value has been assessed at nearly $90-million.

Unifor Local 4276 represents Empress workers in housekeeping, culinary, groundskeeping, serving, guest relations, maintenance and engineering, according to the Union.