OTTAWA — A convoy of truckers set to descend upon Ottawa to protest mandatory vaccinations is prompting police to prepare for violence and politicians to warn against escalating rhetoric linked to the demonstration.

Ottawa police Chief Peter Sloly told a police services board meeting Wednesday that officers had been in been in contact with protest leaders who he said have been co-operative and shared their plans.

But Deputy Chief Steve Bell voiced concern about "parallel groups" that intelligence suggests will also turn up to the protest. The police are trying to reach these groups — as well as counter-protesters — to discuss their aims.

At the meeting, police disclosed they are preparing for a range of scenarios including the potential for violence. Police say they are planning for the arrival of between 1,000 and 2,000 demonstrators on Saturday, but say the situation is "fluid" and changing by the hour. 

Sloly told the board and councillors that he is working with the RCMP and intelligence bodies to prepare for the protests. 

While police support the right to peaceful protest, officers would be prepared to move protesters out of the demonstration zone should the situation become violent or threatening, he said.

Prime Minister Justin Trudeau said there was a "small fringe minority who are on the way to Ottawa who are holding unacceptable views."

Speaking at a news conference Wednesday, the prime minister said the vast majority of truckers are vaccinated.

“What we are hearing from some people associated with this convoy is completely unacceptable,” he added.  

The federal government ended the truckers' exemption to the vaccine mandate on Jan. 15, meaning Canadian truck drivers need to be fully vaccinated if they want to avoid a two-week quarantine and pre-arrival molecular test for COVID-19 before crossing into Canada. 

The Canadian Trucking Alliance has estimated that about 15 per cent of truckers — as many as 16,000 — are not fully vaccinated against COVID-19. It has strongly denounced any protests on public roadways, highways and bridges and has urged all truckers to get inoculated.

Some with extreme, far-right views have latched onto the protest. One online video includes a man expressing hope the rally will turn into the Canadian equivalent of the Jan. 6, 2021, riot at the U.S. Capitol by supporters of former president Donald Trump.

Donald Trump Jr. took to social media Tuesday to endorse the Canadian truck convoy's fight against "tyranny" and to urge Americans to follow suit.

Kayla Preston, who studies the far right in the University of Toronto's sociology department, said the truckers were a magnet for white nationalists as well as people who oppose vaccine mandates.

"Some in the far-right have latched themselves onto the convoy," she said. "The convoy is tapping into the national frustration right now. They are also attracting people who are not part of the far right or white nationalists who are frustrated with COVID."

A group called Canada Unity is organizing the movement, which its members refer to as the "freedom convoy."

A "memorandum of understanding," posted on the Canada Unity website, says its coalition is opposed to restrictions and mandates related to COVID-19, rules it deems are "unconstitutional, discriminatory and segregating."

The memorandum's goal, it says, is to form a committee with the Senate and Governor General that would override all levels of Canadian government to stop the use of vaccine passports, waive fines linked to COVID-19 and reinstate employees who were fired for breaking COVID-19 rules. 

If the Senate and Governor General refuse to join such a committee, the group says they should "resign their lawful positions of authority immediately."

Carissima Mathen, a professor of law at the University of Ottawa, said seeking to override all levels of government policy would not work, because the body who initially put the policy in place must be the one to reverse it. Alternatively, that policy could be undone by Parliament passing a law.

A spokeswoman for the Governor General said Rideau Hall was "keeping on top of the situation and waiting to see how things unfold."

Transport Minister Omar Alghabra said he is "concerned about the small number of far-right, vocal opposition that is polluting much of our political debate."

Some supporters of the convoy, including some Conservative MPs, have taken to social media to warn the vaccine mandate for truckers will leave store shelves empty. Some have gone so far as to predict Canadians will starve.

Alghabra has assured Canadians there's no reason to fear food shortages will result from a small minority of truck drivers refusing to comply with the vaccine mandate.

In an interview, Alghabra said the large grocery store chains and other retailers have assured him they have plenty of goods to provide their customers, despite some labour shortages and supply chain bottlenecks caused by the COVID-19 pandemic.

Moreover, he said there's been no "measurable impact" on the number of trucks crossing the border since the vaccine mandate went into effect. Last week, he said almost 100,000 trucks crossed the border — about the same as usual for this time of year.

"I don't want to minimize the fact that we have to remain vigilant and work together to address these issues (of supply chain disruptions)," Alghabra said, adding he plans to hold a summit on the issue with retailers on Monday.

"But this notion that we're going to starve is really unfortunate and does disservice to Canadians."

A day after refusing to say whether he supported the truck convoy heading to Ottawa, Conservative Leader Erin O'Toole appeared in a Facebook Live event Tuesday evening to say he understands why many truckers, especially independent ones, are upset.

"You can understand why there's some frustration and why people are protesting," O'Toole said.

On Wednesday, the Canadian Federation of Independent Business also urged the federal government to reverse its vaccination policy for truckers. 

Earlier, the Canadian Chamber of Commerce had urged the government to give truckers more time to get vaccinated while the Canadian Manufacturing Coalition has also called for the vaccine mandate to be scrapped entirely.

But Alghabra said it would accomplish nothing to postpone or scrap the requirement that truckers entering Canada be fully immunized, since the United States has imposed the same requirement on truckers entering that country.

The best way to end supply chain disruptions is to end the pandemic and the best way to do that is to get vaccinated, which is what the vaccine mandate is all about, he argued.

This report by The Canadian Press was first published Jan. 26, 2022.

— With files from Stephanie Taylor and Erika Ibrahim

Marie Woolf and Joan Bryden, The Canadian Press