Federal Labour Minister Seamus O’Regan says a strike by the International Longshore and Warehouse Union Canada is illegal after a ruling by the Canada Industrial Relations Board.

In a tweet, O’Regan says the board ordered that the union cease and desist any strike activity because it did not provide 72 hours notice.

The strike that has shut down British Columbia’s ports resumed Tuesday after the longshore workers union rejected a tentative mediated deal.

The International Longshore and Warehouse Union Canada says “employers have not addressed the cost of living issues” faced by workers in the last few years.

The tentative four-year deal that was rejected had been proposed by a federal mediator at the instruction of O’Regan.

O’Regan and Transport Minister Omar Alghabra have said workers and employers across Canada cannot face further disruption and that they are looking at all options.