Canadian police are poised to clear out on Friday hundreds of truck drivers from Ottawa who have staged a three-week-long protest against pandemic restrictions that has crippled the capital and prompted Prime Minister Justin Trudeau to assume emergency powers for the first time in more than 50 years.

The drivers, joined by thousands of demonstrators and some 400 vehicles, turned the streets around Parliament into a noisy party zone since first arriving on Jan. 28, in what has become one of the worst crises to hit Trudeau since he took power in 2015.

Police made a handful of arrests on Thursday evening, including two of the main fundraisers and organizers, Chris Barber and Tamara Lich.

"We absolutely are committed to end this unlawful demonstration. We have the plan, we have the commitment, we have the resources," interim police chief Steve Bell told reporters on Thursday. Police will set up a perimeter with 100 checkpoints around downtown to stop people without legitimate reason from entering, he said.

"This weekend will look very different than the past three weekends," he added. Previous chief Peter Sloly quit this week amid residents' fury about what they saw as police inaction.

The House of Commons suspended its Friday sitting due to the expected police action, it said in a notice. "If you are not in the House of Commons precinct, stay away from the downtown core until further notice," the notice said. The Members of Parliament were scheduled to debate on the Emergencies Act, which needs to be approved by parliament within a week of announcement.

The truckers' protests started as something against vaccine mandates for cross-border drivers, a measure in place in the United States, too. But slowly it spread across Canada and morphed into an anti-government movement. Protesters blocked several land crossings with the United States, including the busiest, the Ambassador Bridge which connects to Detroit, for six days, hurting both economies.

Calling the blockades a threat to democracy, Trudeau on Monday invoked emergency measures giving his government temporary powers to end the unrest. Government officials said they were worried about extremists causing violence.

Many protesters on Parliament Hill said they would not leave until their demands were met.

"End the mandates, give us our rights and this is over," said Chris Dacey on Thursday. "We'll all go back to our families."

The border blockades turned the pressure on Trudeau to act swiftly, and U.S. President Joe Biden asked him to use federal powers.

"The illegal blockades and occupations have to stop and the borders have to remain open," Trudeau told legislators on Thursday as Parliament started debate on the Emergencies Act.

But the official opposition Conservative Party says there was no need for the Emergencies Act, especially since the border blockades are over. Conservative Parliamentarian Jeremy Patzer told the House of Commons on Thursday that people around the world were alarmed to see Trudeau "come down on peaceful protesters with a sledgehammer."

"It is absolutely shameful," he added.