Prime Minister Justin Trudeau's government unveiled legislation Thursday to fully legalize marijuana, making Canada only the second country to do so, after Uruguay.
While medical marijuana use has been regulated in this country since 2001, cannabis remains a controlled substance.
Its legalization and regulation for recreational use is expected in 2018, in time for Canada's national holiday on July 1.
"We know that criminal prohibition has failed," former-police-chief-turned-MP Bill Blair, who spearheaded the initiative, told a press conference.
"Legalization," he said, "seeks to regulate and restrict access to cannabis and will make Canada safer."
According to government statistics, as many as 4.6 million Canadians will consume an estimated total 655 metric tons of cannabis annually by 2018, spending an estimated Can$4.2 billion to Can$6.2 billion (USD $3.15-4.65 billion) each year.
The new regulations closely follow recommendations proposed in December by a task force led by former deputy prime minister Anne McLellan.
They would allow individuals to grow up to four plants at home for personal use.
Personal possession, however, would be limited to 30 grams (one ounce). And access would be restricted to adults 18 years and older.
Public Safety Minister Ralph Goodale warned police would "come down hard" on illicit drug activities.
Trafficking outside the new regime would continue to be illegal and punishable by up to 14 years in prison, as would selling cannabis to youths, driving under its influence, and importing or exporting pot.
The drug has created new enforcement challenges because there has never been a legal or verified scientific test to determine a level of THC -- the psychoactive chemical in pot -- that causes impairment, for example, while driving.
Under the new regime, police would use new roadside saliva or blood tests to determine if a person is intoxicated, a crime punishable by fines or up to 10 years in prison.
- Strong public backing -
The move to legalize recreational use of marijuana is supported by a strong majority of Canadians, but is not without controversy and is sure to provoke a fierce debate in parliament over the coming months.
Trudeau himself admitted in 2013 to having smoked pot five or six times in his life, including at a dinner party with friends after being elected to parliament.
He has also said that his late brother Michel was facing marijuana possession charges for a "tiny amount" of pot before his death in an avalanche in 1998, and that this influenced his decision to propose legalizing cannabis.
Opposition parties are split on the issue. The New Democrats have called for its immediate decriminalization in order to end drug prosecutions they say are causing undue harm and wasting police resources.
A frontrunner for the leadership of the Tories, Kellie Leitch, meanwhile, said she would repeal the bill and reinstate the ban, if elected.
In anticipation of legalization, there has been a rush on licenses to produce medical marijuana, pot stocks have shot up, and dispensaries have opened in cities across the country vying for market share in what promises to be a lucrative business, leading to police raids and calls for sellers to wait for the legal regime.
"It is important to note that as the bill moves through the legislative process, existing laws prohibiting possession and use of cannabis remain in place and they need to be respected," Goodale said Thursday.
"This must be an orderly transition and not a free-for-all."
Health groups have expressed concern about the potential impact of marijuana on developing brains under the age of 25.
But a government-appointed task force has concluded that the "current science is not definitive on a safe age for cannabis use."
Since the intention of legalization is to stop criminalizing users, the government chose an age that would not force adults under 25 to turn to the illicit market.
It noted that in the handful of US states where recreational marijuana use is legal, the minimum age was set at 21, in line with alcohol consumption.
Health Minister Jane Philpott also said that the government has earmarked nearly Can$10 million to educate Canadians about known risks of pot use.