Canada Post workers have embarked on a nationwide strike after the federal government authorised widespread reforms that would shut some post offices and end certain types of deliveries.

The Canadian Union of Postal Workers (CUPW) called the proposed reforms an attack on our postal service and workers as it announced the job action.

The strike by the union's 55,000 members comes amid an ongoing dispute over pay and benefits for postal workers that resulted in a weeks-long walkout late last year.

Canada Post said operations will shut down during the strike, leaving mail and parcels undelivered for millions and adding it would compound the corporation's already dire financial woes.

The sweeping changes announced by the federal government follows years of financial losses sustained by the postal service, which faces reduced demand and stiff competition from private parcel delivery services.

Procurement minister Joël Lightbound stated that Canada Post lost C$1bn ($717; £535m) last year and is on track to lose C$1.5bn this year.

Canada Post is effectively insolvent, and repeated bailouts are not a long-term solution, he said.

The proposed changes will see the closure of several post offices in areas that were once rural and give the service more flexibility to raise prices. The service could also reduce the types of parcels delivered by air and rely more on ground transportation to save costs.

One significant proposal will be ending home deliveries, which will see parcels delivered to community mailboxes instead of in front of people's doors.

An estimated four million addresses still receive that service in the country.

The goal, ultimately, is to save Canada Post, Lightbound told reporters.

The postal workers union said the proposals will only undermine public service and not address the needs of customers.

Canada Post expressed disappointment over the union's decision to escalate the strike activity, stating it would further harm its financial situation.

In a statement on Friday, the Canadian Association of Independent Business warned that the impact of the job action on the country's small businesses would be massive.

Last year's prolonged strike over pay and working conditions remains unresolved, adding complexity to the ongoing negotiations.