OTTAWA — The federal move to invoke the Emergencies Act could allow authorities to forbid more large trucks from rolling into the gridlocked area around Parliament Hill.

The Liberal government's decision Monday to use the law for the first time also gives officials more muscle to shut down gatherings likely to get out of hand and order companies, such as towing firms, to do necessary work.

Prime Minister Justin Trudeau and key cabinet members were short on details at a news conference announcing imposition of the Emergencies Act's public order provisions. As a result, the specific geographic areas to which it would apply were not immediately clear.

They said the measures would be targeted, time-limited and proportionate.

"They will only be applied where they are truly necessary," Trudeau said.

Declaring a public order emergency under the law would give authorities the power to control streets near Parliament Hill now jammed with vehicles, said security expert Wesley Wark.

Wark, a senior fellow with the Centre for International Governance Innovation, said before the announcement Monday it means the government could prevent travel in and out of that protected zone.

Antigovernment blockades have immobilized downtown Ottawa and wreaked havoc at several important border crossings with the United States this month.

The Emergencies Act, passed in 1988, is intended for use when:

— an urgent and critical situation, temporary in nature, endangers the lives, health or safety of Canadians;

— the capacity or authority of provinces to handle the situation is considered lacking; and

— the crisis cannot be defused effectively using other Canadian laws.

The Emergencies Act allows officials to direct people to "render essential services" for reasonable compensation, a power that could help authorities enlist help to move huge vehicles.

"What it means is they could, for example, order tow truck companies to perform essential service in removing trucks blocking the downtown core," Wark said

The Ottawa police have said many towing firms refuse to move the rigs clogging streets due to threats by protesters and the fear of losing future business from the trucking industry.

The emergencies law also permits the regulation or prohibition of any public assembly expected to lead to a breach of the peace.

Philip Boyle, an associate professor at the University of Waterloo who studies public safety, wondered how geographically large a perimeter the law might cast, for instance, in Ottawa's downtown.

Boyle did not foresee sweeping, mass arrests under the provisions. He anticipated police giving people a reasonable amount of time to leave geographic zones singled out under the emergencies law. "And if they don't, then we will see a large number of arrests."

Breaching any order or regulation made through the emergencies law could result in a penalty of up to five years in jail and a fine of $5,000.

The special temporary measures ushered in by the law would be subject to the Charter of Rights and Freedoms, including the protections it affords to people who are arrested.

Noa Mendelsohn Aviv, executive director of the Canadian Civil Liberties Association, said the federal government had not met the threshold necessary to invoke the Emergencies Act.

"Governments regularly deal with difficult situations, and do so using powers granted to them by democratically elected representatives," she said. "Emergency legislation should not be normalized. It threatens our democracy and our civil liberties."

Once invoked, the Emergencies Act requires holding a public inquiry within 60 days after the crisis has ended, and the resulting report being tabled in Parliament within one year.

Wark says that when protests are over, a "deep-diving and very serious" inquiry will be needed to better understand threats to national security and improve laws and enforcement practices.

This report by The Canadian Press was first published Feb. 14, 2022.

Jim Bronskill, The Canadian Press