Health Minister Rona Ambrose says a new anti-drug campaign isn't asking doctors to take a partisan view on marijuana. She says if anything, it's Liberal Leader Justin Trudeau who has politicized the issue.

Ambrose's comments come after three groups that represent Canadian doctors – the College of Family Physicians of Canada, the Canadian Medical Association and the Royal College of Physicians and Surgeons of Canada – declined to take part in Health Canada's upcoming anti-drug campaign targeting young people.

In a joint statement issued on Saturday, Canada's doctors said they were invited "to co-brand and provide expert advice” on the public campaign, initiated and funded by Health Canada.

"The educational campaign has now become a political football on Canada's marijuana policy and for this reason the CFPC, CMA and Royal College will not be participating. We did not, and do not, support or endorse any political messaging or political advertising on this issue," Canada's doctors said.

Ambrose spoke about the marijuana smoking cessation campaign for youth on Monday following a speech in Ottawa to the Canadian Medical Association — one of the three groups that said it would not be taking part in Health Canada's anti-drug campaign.

"Telling kids not to smoke marijuana is not politics, it is good public health policy and it's based on science," the minister said.

Despite several Conservative ads attacking Trudeau for his stance on legalizing marijuana in recent weeks, Ambrose said it was Trudeau who is politicizing the issue.

"Justin Trudeau made this a political issue by saying Health Canada's anti-marijuana campaign was a thinly veiled attack on him," Ambrose said.

Trudeau complained the Conservatives are using public money to attack him.

"We know that taxpayers are getting extremely frustrated with the fact that this government tends to use public money for ads that do more for its partisan aims than for actual public service," he said in Saskatoon last week.

Ambrose rejected Trudeau's criticism.

"Telling kids to not smoke pot is not a partisan attack on Justin Trudeau by Health Canada. It is a sound public health policy backed by science," she said on Monday.

"Whether pot is legal or illegal, the health risks of marijuana to youth remains the same and we should all be concerned about them."

She urged doctors to get on the same page as Health Canada.

"I encourage the medical community to be very clear on their message so we don't send a mixed message," Ambrose said.

Dr. Louis Hugo Francescutti, the president of the Canadian Medical Association, told reporters in a separate news conference doctors are well aware of the dangers of marijuana use by young people.

"The evidence is pretty well irrefutable."

Contrary to Ambrose's assertion, Francescutti said, the anti-drug campaign did have a political tinge to it leading doctors to distance themselves from it.

"The campaign, unfortunately, took a twist that looked a little political. And as a non-partisan organization, we heard from our members loud and clear that they did not want us to be affiliated with a campaign like that."

Francescutti said the medical association will continue to tell Canadians about the dangers of marijuana use by young people and "not get sidetracked" from their agenda.

Ambrose told reporters the initiative came from the doctors, but the CMA also rejected that assertion.

“The Canadian Medical Association called for a national marijuana-smoking cessation campaign for youth and I agreed. Health Canada’s campaign is in response to that," Ambrose said.

In a late statement issued on Monday, the group responded by saying "the CMA is on record as calling for a public education campaign on the dangers of marijuana use by youth.

"We did not ask for a multi-million-dollar taxpayer-funded advertising campaign to be turned into a political football."