The former Canadian ambassador to China says he believes Montreal Pride should have protected a group of pro-democracy Hong Kongers instead of banning them from the parade earlier this month.

David Mulroney said organizations such as Pride should be interested in and supportive of human rights battles around the world.

"I think this was a major fail," he said.

FREE HK MTL, a group of activists supporting the pro-democracy movement in Hong Kong, was approved to march in the Pride parade in the leadup to the Aug. 18 event.

The day before the parade, organizers banned the group from marching because they say they received at least 10 threats on social media and in emails. The nature of the threats is unclear.

Montreal Pride told the group it had received information from police about "a potential attempt to sabotage the parade by pro-Communists."

Mulroney said events like the Pride parade often face counter-protests and organizers usually respond by ensuring security is informed and prepared.

He added the situation sounds like a typical Chinese disinformation campaign, where unspecified threats are made in order to shut down independent voices.

"We have to be worried, especially when we come upon a case where the whole intent seems to be to stifle free speech," he told CBC News.

"That's classic United Front work, and it represents a kind of bullying and a shutting down of discussion."

The Chinese Communist government uses an agency called the United Front Work Department to spread information — and nationalist propaganda — overseas.

In an email, a spokesperson for the Chinese Embassy in Ottawa said they learned about the incident through media reports, and referred questions to the event organizer.

Suspicions of Chinese influence mounting

Former national security analyst Stephanie Carvin says that without more information on the exact nature of the threats, it's difficult to know how serious they were.

"The best-case scenario is that [Pride] was afraid of political embarrassment," Carvin said. "Worst-case scenario is that there was a physical threat potentially organized in a clandestine way by groups that may have had links with Chinese diplomatic sources."

Henry Lam, right, and his husband Guy Ho travelled from Hong Kong to Vancouver to get married eight years ago. They weren't allowed to march in Montreal's Pride parade two weeks ago. (Simon Nakonechny/CBC)

Carvin says the spreading of this propaganda often happens person-to-person, with Chinese nationalists living in Canada organizing protests in collaboration with Chinese consulates.

Suspicions of Chinese government influence being exerted in Canada, especially on university campuses, is mounting.

In February, a speech by an activist critical of the Chinese government's treatment of Uighurs was disrupted by students at McMaster University .

In that case, neither the Chinese consulate nor the embassy returned CBC's requests for comment.

The activist, Rukiya Turdush, was adamant that students who filmed and shouted during her talk did so under the direction of the Chinese government.

Also in February, a campaign of online vitriol was launched against Tibetan activist Chemi Lhamo, who was elected student president at the University of Toronto's Scarborough campus. Chinese officials denied involvement in that incident.

Politicians shouldn't be priority, says Mulroney

Several politicians participated in the Montreal Pride parade, including Quebec Premier François Legault and Prime Minister Justin Trudeau.

Mulroney said the fact that Pride used the presence of politicians as a reason to prevent the Hong Kong group from marching is inherently problematic.

"The idea that you can't have human rights marchers in a parade that purports to be about human rights because politicians are going to be there is patently ridiculous."

Prime Minister Justin Trudeau, centre, attended the Pride parade this year along with Quebec Premier François Legault, Montreal Mayor Valérie Plante and other politicians. (Graham Hughes/The Canadian Press)

He says he hopes Montreal Pride will review its criteria for membership, and that this type of "intimidation" never happens again.

Trudeau's staff told The Canadian Press the prime minister's office was not consulted or informed about any decisions related to parade participants. Legault's office declined comment.

Focus of Pride should be LGBTQ community: Pride VP

Montreal Pride vice-president Jean-Sébastien Boudreault told CBC he's aware the message the Hong Kong group is trying to convey is very important, and that his organization knows the seriousness of the pro-democracy protests happening in Hong Kong, but the focus of Pride had to remain on LGBTQ communities.

"We had the choice to make between taking a risk of having people disturb the parade, stopping the parade, or asking a group whose message was not entirely focused on LGBTQ [not to participate]."

He said if Montreal Pride gets involved in all the political and geopolitical conflicts in the world, the organization's initial message of LGBTQ inclusivity and pride will be erased.

Boudreault travelled to Hong Kong in April to meet with organizers from the Pride parade there. Montreal Pride paid for them to come to the parade, and paid to advertise their parade to Montrealers.

"We are supporting LGBTQ people all over the world," Boudreault said. "We didn't want to take the spotlight away from the LGBTQ rights and events."