Manitoba Premier Brian Pallister is rallying support among his provincial and territorial counterparts to demand the federal government hit the brakes on its plan to legalize pot.

Pallister, who is attending the Council of the Federation meetings in Edmonton, said there are questions that must be answered before the "historic change" is brought into force. He wants to delay the implementation by one year.

"I think that there are too many unaddressed issues that need to be paid attention to for us to hurry into something like this, [given] the magnitude of this," he said.

The federal government has said it plans to pass legislation legalizing cannabis, which was tabled this spring, by July 2018.

A spokesman for Justice Minister Jody Wilson-Raybould told CBC News last week that target remains, and that people living in provinces where distributors are not yet in place by that time will have access to recreational pot by mail delivery.

Pallister said provinces need more time to ensure proper roadside testing is in place to keep drug-impaired drivers off the roads, and to educate the public about the perils of getting behind the wheel high.

Manitoba Premier Brian Pallister is pushing to delay the legalization of marijuana by one year. (Kathleen Harris/CBC)

"These are not well understood. For us to rush into this, we're putting tremendous risks at play, we're also putting tremendous costs into the provinces' hands," he said.

Pallister also believes there should be a standard age for legal access to cannabis across Canada, instead of the "hodgepodge" that now exists for alcohol across the country.

'Moving parts'

Ontario Premier Kathleen Wynne and Quebec Premier Philippe Couillard said the group will have further discussions on legalized pot tomorrow, but said their provinces are working towards meeting the July 2018 deadline.

Saskatchewan Premier Brad Wall said his province would not object to an extension.

"There's a lot of moving parts here," he said.

He said it will be difficult to pull off standardized rules around labelling, road safety and age of access across the country in such a short period of time.

Alberta Premier Rachel Notley, who is chairing this year's Council of the Federation meeting, did not want to pre-empt discussions on the topic slated for Wednesday, but said premiers are facing big policy decisions and major challenges implementing the changes. She said Alberta will work to meet the deadline but did not rule out asking for an extension.

"Certainly from the perspective of Alberta we're focusing on reaching those timelines, but we're also signalling that there will be a challenge to do that," she said at a news conference to close today's meeting.

Pot an 'economic opportunity'

New Brunswick Premier Brian Gallant said the federal government's goals of getting marijuana out of the hands of youth and organized crime are valid, and suggested it could be a money maker for some provinces.

"We also see it, once we have put the proper regulations and enforcement of those regulations in place for production, distribution and sales, this is an economic opportunity," he said.

The federal government has set 18 years old as the minimum age to access marijuana. Nova Scotia Premier Stephen McNeil has said it would be beneficial to have a uniform age across the country.

"I believe 19 makes sense," he said, adding that he's "more than prepared to have a conversation with my fellow premiers and, quite frankly, the citizens of our respective provinces to make sure that we hear their voices and come up with what will be palatable to everyone."

Canada already has laws against drug-impaired driving. But when the justice minister introduced the cannabis legalization bill this spring, she also proposed major changes to impaired driving laws.

Saliva tests

The bill would allow police to demand a driver provide a saliva sample if they suspect a driver is drug impaired. A positive reading could lead to further testing, including a blood test.

The bill also creates three new drug-related offences for drivers who have consumed drugs within two hours of driving.

Some premiers and stakeholders say they need more time and resources to make sure police have the tools and training to deal with a potential increase in pot-impaired driving when cannabis becomes legal.