Drivers are being warned to expect significant traffic delays on major highways from Thursday to Saturday as the "Freedom Convoy" of truckers enters Ontario.

The Ontario Provincial Police said delays are expected on the QEW, Highway 400, Highway 427, Highway 403, and Highway 401 over the next few days.

The group of truckers began a cross-country trip in British Columbia on the weekend and are headed to Ottawa. They are protesting mandates that require truck drivers crossing the Canada-U.S. border to be vaccinated.

"Be aware there could be significant traffic delays through provincial highways," OPP Sgt. Kerry Schmidt said Wednesday. "If you are motorist, plan ahead and expect delays."

Schmidt said the group of truckers have the right to peacefully protest, but police will keep a close eye to ensure drivers remain safe.

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.

Others, with more 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.

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.

With files from The Canadian Press.