With long-awaited marijuana legislation set to be announced next week, the federal government is having second thoughts about legalizing cannabis on Canada Day.

The Trudeau government still plans to go ahead with its plan to make weed legal for recreational use. But a senior government source says the initial target of July 1, 2018 as the implementation date will be changed to "on or before July 1, 2018."

The change reflects some internal concerns over legalizing a recreational drug on the country's birthday. Bill Blair, the Liberal government's point man on pot, told the Canadian Press he wanted the focus of Canada Day to be Canada — not cannabis.

"I'm probably out on a limb on this one but ... I don't believe July 1 should be an implementation date for anything; it is a day of celebration for the anniversary and founding of our country," Blair told CP.

"I don't think that's an appropriate date. That's my opinion."

By next summer

But what isn't changing is the federal government's desire to fully deliver on its marijuana legalization promise by next summer — despite suggestions that the timeline may be too ambitious.

The federal government believes its timeline to have a nation-wide system for the distribution and sale of marijuana is achievable — even though much of the heavy lifting will have to be done by the provinces.

"We campaigned on this," said the senior government official. "We told them it was going to happen."

Bill Blair, parliamentary secretary to the Minister of Justice, told the Canadian Press he doesn't think Canada Day 2018 is an appropriate date for legalising marijuana. (Sean Kilpatrick/Canadian Press)

It appears that Ottawa is counting on the potential profits from marijuana sales to speed things along at the provincial level. Colorado legalized marijuana in 2014 and, with a population smaller than Quebec and Ontario, that state is doing more than $1 billion US in legal sales a year.

The hope is that at least a few of the provinces will move quickly to finalize their system for retail sales and that will have a pace-car effect for the slower moving jurisdictions.

Bill details coming next week

The marijuana legislation is set to be unveiled next week. But CBC News reported many of the details last month. It will broadly follow the recommendation of a federally appointed task force that was chaired by former liberal Justice Minister Anne McLellan.

The federal government will be in charge of making sure the country's marijuana supply is safe and secure and Ottawa will license producers.

But the provinces will have the right to decide how the marijuana is distributed and sold. Provincial governments will also have the right to set the price.

While Ottawa will set a minimum age of 18 to buy marijuana, the provinces will have the option of setting a higher age limit if they wish.

As for Canadians who want to grow their own marijuana, they will be limited to four plants per household.

Legalizing marijuana was one of the more controversial promises Prime Minister Justin Trudeau made as he campaigned to become prime minister.

In their platform the Liberals said it was necessary to "legalize, regulate and restrict access to marijuana" in order to keep drugs "out of the hands of children, and the profits out of the hands of criminals."

The Liberals had promised to introduce legislation by the Spring of 2017. Announcing the legislation next week will allow the party to hit that deadline.