Justice Minister Peter MacKay says Justin Trudeau’s credibility is “up in smoke” after the federal Liberal Party leader admitted smoking marijuana around the time he voted in the House to increase penalties for pot possession.

Trudeau sparked an uproar Thursday, after the Huffington Post published remarks from an interview in which he said he had smoked marijuana about a half-dozen times. The last time, he said, was three years ago when friends passed a joint around a backyard party he and his wife were hosting. He also acknowledged that his experiences smoking pot corresponded with votes he cast in the House in 2009 supporting mandatory minimum sentences for marijuana possession.

On Thursday, MacKay issued a statement that said Trudeau’s admission he smoked weed while a Member of Parliament “demonstrates a profound lack of judgment,” and called the Liberal leader a “poor example for all Canadians, particularly young ones.”

In Halifax on Friday, MacKay elaborated in a question-and-answer session with reporters.

“It’s currently against the law to smoke dope. I think most Canadians expect that their Member of Parliament will obey the law,” MacKay said, acknowledging that the private lives of public figures are “increasingly under scrutiny.”

“But this admission of smoking marijuana, breaking the law, doing so knowingly while he was a Member of Parliament, the politics of this are such that there’s an element of hypocrisy of having voted on the record to increase penalties around the same time that he was lighting up. So his credibility is a little up in smoke.”

When asked by reporters Friday whether he had used any drugs since becoming an MP, Foreign Affairs Minister John Baird smiled and said: “No. No.”

He explained to his visiting Indonesian counterpart, Marty Natalegawa why he was being asked about drug use, and assured Natalegawa that he would not let reporters ask him the same question.

“Listen I think politicians are entitled to private lives,” Baird said, “but the answer would be an unequivocal no.”

In the Huffington Post interview, Trudeau discussed how his opinion of marijuana has evolved over the years, from supporting decriminalization to calling for legalization to keep it out of the hands of children. He also says tax revenue from marijuana will help boost government coffers.

When asked by reporters about the interview and whether his past pot use had been a mistake after a meeting with Quebec City Mayor Regis Labeaume Thursday, Trudeau said, “no.”

"I do not consume cannabis,” he said. “I am not a big consumer at all. I tried it.”

He also said he has never tried other types of hard drugs, and is not much of a drinker. A comment that he also abstains from coffee led to much teasing on Twitter, including questions about whether his lack of caffeine consumption left him fit for higher office.

When asked about Trudeau’s comments during his trip to the Arctic Thursday, Prime Minister Stephen Harper said the Liberal leader’s actions “speak for themselves” and offered no further comment. His office had previously told the Huffington Post that Harper’s asthma had precluded him from smoking anything. NDP Leader Thomas Mulcair’s office clarified Thursday that he has smoked pot but not since he was first elected to public office in 1994.

In the end, Trudeau made light of the whole uproar by tweeting: “Realizing I may have made a major mistake in my openness and transparency: vicious attacks coming because I don’t drink coffee #oops.”