Dockworkers in Montreal have announced a strike that will shut down container terminals at eastern Canada’s busiest port.

The Maritime Employers Association, which is made up of container ship and terminal operators, said it received a strike notice from the Port of Montreal Longshoremen’s Union on Thursday.

The 24-hour strike will begin at 7 am local time (11:00 GMT).

The move comes just weeks after a previous strike shut down Termont’s Viau and Maisonneuve terminals, where MSC Mediterranean Shipping Company is the largest user.

The employers’ association said the latest strike includes the Contrecoeur terminal.

“The strike that began October 10, 2024, at 7 p.m., which completely halted overtime in all its forms, is still ongoing and continues to cause damage,” the group said.

“These pressure tactics applied by the Union have created significant operational problems, which are in addition to a number of obstacles that are seriously affecting stability and reliability at the Port of Montreal as well as in the Quebec and Canadian supply chain.”

The 1,200 dockworkers are part of the Canadian Union of Public Employees (CUPE). Their collective bargaining deal expired 31 December.

On 10 October, the union refused overtime work for an unlimited period as it called for better scheduling and work-life balance.

Union representative Michel Murray said at the time that the workers were ready for “intensive” negotiations but that the employers were dragging their feet.

The employers’ association complains that the labour uncertainty at the port has “major ramifications” and has contributed to a 24% cargo decrease since 2022.

“Longshore work is an age-old trade, but the time has come to bring it into the 21st Century and modernise the archaic practices at the port. Solutions are at hand, but there must be a willingness to hear them and be at the table to negotiate them,” Murray said.

Canadian labour and seniors minister Steven MacKinnon has proposed a 90-day cooling off period and the appointment of a federal mediator to help overcome the impasse.

But he withdrew the proposal when no agreement to appoint a mediator could be reached.

“After 35 mediation meetings over 15 months, it is clear that the parties are still at square one and at an impasse,” the employers’ group said.