Canadian Union of Postal Workers said it went on a nationwide strike on Thursday after the Canadian government called for the postal company to undergo a widespread transformation to bolster its finances and modernize operations.

Canada Post said that its operations will be shut down following the strike, and that its customers can expect delays.

Earlier on Thursday, the Canadian government instructed Canada Post to begin major changes to its operations, saying that the company faces structural challenges, which — coupled with outdated restrictions and stalled negotiations between labour and management — have limited its ability to adapt, causing mounting losses.

The union said in a statement that the announcement made by the minister responsible for Canada Post, Joel Lightbound, gave no clear details about how changes would be implemented to the organization, and warned that the recommendations — which include community mailbox conversions, among others — could result in major job losses and changes to delivery standards.

CUPW said it was informed that Canada Post needs until next week to present new global offers.

In response to the strike, the Canadian Chamber of Commerce called for a return to the bargaining table for negotiations in good faith.