On the day pot smokers gather annually to celebrate, the Liberals announced they will introduce their much-anticipated marijuana legislation in the spring of 2017.

However, Prime Minister Justin Trudeau refused calls on Wednesday to decriminalize the drug while the legislation is being developed.

NDP Leader Tom Mulcair demanded in daily question period Wednesday to know whether the Liberals will prevent those caught with small amounts of pot from incurring criminal records while it remains illegal.

Trudeau responded that he believes in legalization “because it protects our kids and keeps money out of the pockets of criminal organizations and street gangs,” but suggested he is opposed to decriminalization.

“The fact of the matter is, decriminalization actually gives a legal stream of income to criminal organizations,” Trudeau said. “That’s not what anyone wants in this country.”

The stance puts the prime minister at odds with some in his own party, including Toronto MP Nathan Erskine-Smith, who studied decriminalization at Oxford University and has advocated for decriminalization, including at a United Nations conference in February.

Mulcair later told CTV’s Power Play that “thousands of people” have received criminal records since the Liberals were elected due to small amounts of marijuana, and some of them may be young people who believe pot has already been decriminalized.

“By the time this thing gets done, tens of thousands of people will have criminal records,” he said. “And by the way, it’s not a good use of our police or our court system.”

“If Mr. Trudeau truly believed that the best solution was continuing to keep it criminal, he should have had police arrest people on the hill here today,” Mulcair added, referring to the 4-20 celebration on Parliament Hill. “It’s a mixed signal that has been sent.”

Health Minister Jane Philpott was at the UN General Assembly in New York on Wednesday, when she announced the spring 2017 timeline.

Philpott told a special session on global drug policy that the Liberal government’s plan to legalize and regulate pot “challenges the status quo in many countries.” But the government is convinced that it is the best way to “protect our youth while enhancing public safety,” she said.

"I am proud to stand up for our drug policy that is informed by solid scientific evidence and uses a lens of public health to maximize education and minimize harm."

Philpott, who was a family physician before she entered politics, said she has seen “too many people suffer the devastating consequences of drugs, drug-related crime and ill-conceived drug policy.”

She said the new legislation will keep marijuana “out of the hands of children, and profits out of the hands of criminals.”

Philpott made the announcement on April 20, or 4-20, an annual day of marijuana celebration around the world. Across Canada, pot smokers lit up at 4:20 p.m.

Raitt says ‘we have to see it’

Although the Conservatives under Stephen Harper opposed changing the law, MP Lisa Raitt told CTV’s Power Play Wednesday that her party “will look at what the legislation does.”

“What we will do as the opposition is bring up where we see weaknesses and put forth amendments where we see fit,” she said. “But we have to see it.”

Raitt said she doesn’t believe the prime minister’s assertion that legalization will keep the drug out of the hands of children, adding, “he’s going to have to live up to that promise and he’s going to need one heck of a piece of legislation for that to happen.”

Raitt also said she has concerns about marijuana in the workplace and the dangers of driving while high.

NDP MP Nathan Cullen – who told Power Play he’s “still thinking” about whether to run for his party’s leadership -- said he saw many teenagers using marijuana at the 4-20 celebration on Parliament Hill earlier in the day, “so clearly the access is there.”

“Now the question is, what are we doing with people now who are being criminally charged for small possession while the government works through a one or two year process on their legalizations?” he added.

Liberal MP Marco Mendicino, who has worked as a criminal lawyer, said he has seen first-hand that the current system is “not working … for vulnerable communities, for minorities, for impoverished communities, and we can do better.”

“One of the ways we can do better is by tightly regulating and restricting access to these groups, and especially children,” he said.

The Toronto MP said he was “encouraged to hear” Raitt shares common goals, including “ensuring we keep marijuana out of the hands of children, out of the hands of the vulnerable and also making sure we’re regulating it in a responsible way when it comes to drivers on the road.”

Speaking to reporters in Ottawa on Wednesday, Conservative public safety critic Erin O’Toole said the Liberals are making “a bold promise” on marijuana with no “real thought about international ramifications” and concrete plans to sell and regulate pot.

“We’d like the government to start articulating how they’re going to do this, how they’re going to regulate it and how they’re going to ensure that young people aren’t…exposed and able to procure (marijuana),” he said.

With files from The Canadian Press and Sonja Puzic