The province's highest court says Victoria didn't follow proper procedure in implementing a bylaw prohibiting the use of single-use plastic bags, and has struck it down.

The bylaw, passed in December 2017 and implemented in July 2018, prevented retail outlets from offering or selling single-use plastic bags to customers, and imposed a minimum 15-cent charge for paper bags.

With the bylaw quashed, Victoria Mayor Lisa Helps said she hoped businesses wouldn't bring back plastic bags, as she vowed to bring the ban back.

"Victorians care deeply about this issue and they told us that single-use plastic bags do not align with their values," Helps said Thursday.

Helps argued cities do have the authority to regulate businesses and their sustainable practices. The city will be reviewing the decision. She added an estimated 17 million bags were stopped from going into landfills thanks to the ban.

"Businesses and residents have embraced the transition to reusable bags. It's been a tremendous success. We will continue our efforts to phase out single-use items," added Helps.

The bylaw was challenged by the Canadian Plastic Bag Association, arguing the city didn't have the authority to ban a product from distribution or financially impact manufacturers. In a statement, the association says it is "pleased" with the ruling, and will continue to review it.

Today's decision overturns a B.C. Supreme Court ruling in favour of the city.

In a unanimous ruling, the B.C. Court of Appeal found that the city moved ahead with the ban without the B.C. environment minister's approval.

"While the city's intentions in passing the bylaw were no doubt reasonable, we must give effect to the clear instructions of section 9.3 of the Community Charter requiring the minister's approval," the judge wrote in her decision.

In a statement, the Ministry of Environment and Climate Change Strategy wrote it was reviewing the decision. Adding, "British Columbians are concerned about plastic waste in our environment and want action. To that end, the Province is currently looking at ways to prevent plastic waste in our environment at a province-wide level."

Municipalities across B.C. and Canada are already introducing programs to eliminate single-use plastic bags, an encouraging sign for Helps.

This week, the City of Vancouver launched public consultations around banning plastic bags. In a statement, the city said staff "are studying the decision to determine how it affects Vancouver."

"Vancouver is not governed by the same legislation that governs Victoria's bag ban," The city wrote. "The city's authority over this issue is found in the Vancouver Charter, which was not the subject of this litigation."

Lawyer Ryan Parsons, with Eyford Partners, who represented the Canadian Plastic Bag Association told CTV news if other municipalities have bylaws where the primary purpose was to protect the environment and they didn't get sign-off from the Minister, they could also be vulnerable to similar legal action.