Elon Musk voiced his support for a so-called “freedom convoy” of Canadian truckers and other activists on their way to Ottawa to protest the country’s vaccine mandates and other Covid-19 control measures.

“Canadian truckers rule,” the Tesla Inc. chief executive officer said Thursday in a tweet, a clear nod to a convoy that’s been picking up attention around the world. The truckers have drawn the praise of Donald Trump Jr. and been featured on Fox News in the U.S.

It’s unclear how many trucks will actually make it to the Canadian capital for the weekend protest, with the convoy slowed by winter weather conditions in Northern Ontario. Police reports from along its path suggest the number is in the hundreds, much lower than supporters’ claims of thousands of vehicles en route.

Musk’s dislike of vaccine mandates and other Covid restrictions is well documented. He told Time Magazine that while he and his eligible children are vaccinated, state-imposed requirements to get a jab represent an “erosion of freedom.”

Prime Minister Justin Trudeau’s government implemented a vaccine mandate for truckers crossing the Canada-U.S. border on Jan. 15, and the U.S. followed a week later.

Although the new rules sparked concern of a further disruption to supply chains, the Canadian Trucking Alliance has said about 90% of truckers in the country are vaccinated. The industry group also said it “strongly disapproves” of protests that disrupt transportation routes.

Trudeau, who is now isolating after being exposed to Covid, disparaged the convoy during a press conference on Wednesday.

“The small fringe minority of people who are on their way to Ottawa, or who are holding unacceptable views that they’re expressing, do not represent the views of Canadians who have been there for each other, who know that following the science and stepping up to protect each other is the best way to continue to ensure our freedoms,” the prime minister said.

Jason Kenney, the Conservative premier of the oil-producing province of Alberta, has criticized the Canadian and U.S. governments’ vaccination requirement on truckers, claiming it’s resulted in empty supermarket shelves and higher costs for consumers. He was traveling to Washington on Thursday to attend a meeting of U.S. governors and meet with political leaders to advocate for a lifting of the vaccine requirement, he said in a press conference.

“We don’t think there is any compelling public health reason for this,” he said. “The vast majority of truckers are vaccinated, and the governments had granted a multi-month exemption to this rule. We simply ask them to restore that exemption.”