The government's proposed anti-terror law will almost certainly face legal and constitutional challenges on multiple fronts, according to witnesses who appeared before the House public safety committee on Thursday morning.

Former Security Information Review Committee (SIRC) chair Ron Atkey warned MPs that the provision to allow CSIS agents to apply for federal court authorization for measures that could potentially contravene a charter right is a "major flaw" in the proposed legislation.

"That provision, in my view, is clearly unconstitutional, and will be struck down by the courts," he told the committee.

"If Parliament wants to invoke the notwithstanding clause, it is free to do so under this Constitution, although no federal Parliament has had the courage or the need to do so since the charter was proclaimed in 1982," he added.

"But why provoke an avoidable constitutional challenge?" he wondered.

"Canadian judges are fiercely independent, and are not agents of the government who can be mandated to authorize measures at all costs to protect against terrorist threats."

Ron Atkey, who served as the first chair of the Security Information Review Committee (SIRC), warned that provisions allowing CSIS agents to ask the federal court to authorize activities that could breach charter rights will almost certainly be struck down by the courts. (CBC News)

Describing the proposed section as drafted as a "constitutional mess," Atkey suggested that it be rewritten to make it clear that judges would not be asked to authorize actions that risked violating charter rights.

Speaking with reporters before question period, Justice Minister Peter MacKay maintained the bill was constitutional.

"As we do with every bill, there’s a thorough and vigorous vetting of the legislation to see that it’s charter-compliant, that it is consistent with the Constitution, and I can assure that it’s happened in this instance," he said.

"We have people at the Department of Justice who are well-versed and experienced in legislation and drafting to see that we meet that standard."

First Nations to challenge law

Meanwhile, Assembly of First Nations National Chief Perry Bellegarde said the government's failure to consult with First Nations people during the drafting process will likely also trigger a challenge.

"The process for developing this legislation did not meet the federal government's duty to consult and accommodate," he told the committee.

"On that point alone, it is subject to challenge in the courts if the government tries to impose it on us."

He called on the government to withdraw the bill immediately in order to "properly consult" with First Nations people.

Bellegarde also voiced his fear that the "overly broad" new definition of terrorism is a "euphemism to allow them to spy on First Nations" that goes "way beyond" the current Criminal Code definition.

"This is not an abstract argument for our people," he noted.

"We have been labelled as terrorists when we stand up for our rights and our lands and our waters."

The committee also heard from Greenpeace Canada executive director Joanna Kerr, who outlined why she, too, fears the bill could target peaceful if not necessarily lawful protests as potential terrorist threats.

"Would women have the vote today if the suffragettes had not engaged in widespread non-violent protest?" she asked the committee.

"Would racial desegregation in the United States have occurred without sit-ins, marches, public protests and peaceful sustained resistance to unfair laws?"

In the name of national security, the new powers to be extended to law enforcement could be used to "target democratic protest movements," Kerr warned — including anti-pipeline protesters and First Nations activists, she suggested.

"Based on evidence from public statements by cabinet ministers, as well as leaked RCMP and government documents, there is strong reason to suspect these powers could and would be used against those advocating for clean water, precious ecosystems and an end to catastrophic climate change," she said.

Government defends bill

Public Safety Minister Steven Blaney had done his best to pre-emptively dismiss those concerns during his appearance before the committee on Tuesday.

"The leader of the NDP has alleged that the legislation before us today means that legitimate dissent and protests would now be considered threats to Canadian security," he noted at the time.

"These allegations are completely false, and, frankly, ridiculous"

The act, he continued, "clearly states that the definition of activity that undermines the security of Canada does not include lawful advocacy, protest, dissent or advocacy expression."

During Thursday's session, Conservative committee members, including Blaney's parliamentary secretary, Roxanne James, offered similar rebuttals to the witnesses.

"Unless your lawful protest is going to somehow involve blowing up infrastructure, I think you're misinterpreting that part of the bill," James suggested during an exchange with Greenpeace campaigner Keith Stewart.

And while Privacy Commissioner Daniel Therrien may not have made the short list of witnesses, some of his major concerns were brought the committee table by others.

No-fly list expansion questioned

Describing the bill as "fundamentally flawed," BC Civil Liberties Association lawyer Carmen Cheung warned that the "radical conception of 'security'" being contemplated would authorize "warrantless information sharing across government" — and even, potentially, beyond.

Such "massive data collection and information sharing may not benefit security," she added.

She also criticized the enhanced no-fly provisions.

"Travellers on such lists are deemed too dangerous to fly, yet too harmless to arrest," she noted.

"It is our view that if law enforcement officials have enough information to determine that an individual poses a threat to aviation safety, or that they are planning to board a plane in order to commit a terrorism offence, they are also likely to have enough information to lay charges or seek a recognizance order with conditions."

University of Calgary professor Barry Cooper also appeared during the morning session, and although he was more supportive of the bill than his fellow witnesses, he, too, saw room for improvement, including increased oversight that would cover all national security agencies — a sort of "super SIRC," as he put it, that could also include a role for parliamentarians.

He also expressed some concern that giving CSIS increased power to 'disrupt' could potentially jeopardize efforts by the RCMP to compile sufficient evidence to allow a suspected terrorist to be arrested.

This evening, the committee will hear from law professors Craig Forcese and Kent Roach, who have been churning out extensive analysis on the bill since it was tabled earlier this year, as well as National Airlines Council of Canada executive director Marc-Andre Rourque and National Council of Muslims executive director Ihsaan Gardee.