If the Conservatives win the 2019 federal election and try to undo cannabis legalization, the party will face “very substantial backlash,” Public Safety Minister Ralph Goodale warns.

Conservative Leader Andrew Scheer has not committed to keeping cannabis legal if his party forms government next year. Scheer accused Prime Minister Justin Trudeau on Wednesday of taking a “rushed” approach to legalization and told CTV’s Power Play on Thursday that a Conservative government would “examine the reality on the ground” on cannabis and go from there.

Public Safety Minister Ralph Goodale cautioned Scheer that reversing legal cannabis would effectively “recriminalize” people. Goodale suggested Scheer “think very carefully about that.”

“Does he want to recriminalize Canadians? I think he would face a very substantial backlash,” Goodale told CTV’s Question Period.

Other prominent Conservatives think pot is probably here to stay.

Conservative Health Critic and Ontario MP Marilyn Gladu said a Tory government would likely be unable to scrap the legal cannabis system for several reasons.

“It'll be very difficult to reverse the legalization because you know provinces and municipalities have put their rules in place and Canadians are invested, so I think it's unlikely, but certainly we'll listen to what Canadians have to say,” Gladu told CTV’s Question Period on Sunday.

Sources told CTV News that Scheer’s wait-and-see stance sparked internal debate within his office. Some members of Scheer’s team wanted him to clearly state that he won’t reverse legal cannabis, according to sources, and urged him instead to focus on public education and health risks.

Conservatives almost unanimously opposed Bill C-45, the cannabis legalization bill, in the House of Commons. Only one Conservative MP, Ontario MP Scott Reid, supported the bill. All others either voted against the bill or abstained from voting.

Cannabis sales began across Canada last Wednesday, and government-approved dispensaries are still opening in several provinces. According to Statistics Canada, non-medical cannabis sold in the black market was worth about $3.3 billion in 2016.

Gladu has raised concerns about the national rollout and says the Liberal government needs to ensure that cannabis products sold online aren’t attractive to young people. Critics have been quick to point out playful names of cannabis products, including strains such as Shishkaberry, Super Sonic and Blueberry Kush.

"The sprit of the regulation was that they did not want the packaging in any way to be attractive to young people," Gladu said Friday.

"The government keeps saying they wanted to keep this out of the hands of youth."

Former Conservative Prime Minister Brian Mulroney has taken a markedly different approach than Scheer to cannabis. Mulroney is joining the board of directors of Acreage Holdings, a U.S. cannabis company, in November.

Mulroney says he expects the rest of the world will be closely watching cannabis legalization in Canada and could eventually follow suit.

“My guess is that…other countries are going to seek to emulate what Canada has done here,” he said.

Asked if he plans to smoke cannabis under the new rules, Goodale said he’s never tried marijuana and doesn’t expect to change.

With files from CTV’s Question Period and The Canadian Press