OTTAWA -- The federal government's omnibus security bill would hand extremists what they want by shackling civil liberties, a prominent aboriginal lawyer and activist says.

There is no way to fix the legislation, which "makes us all suspects," said Pamela Palmater, chair in indigenous governance at Toronto's Ryerson University.

"The terrorists will have won," Palmater said Tuesday during a meeting of the House of Commons public safety committee, which is hearing more than 50 witnesses on the bill.

"And what is terrorism? Fundamentally, it's the denial of life, liberty and security of the person. If Canada goes ahead and takes those rights away, terrorists just have to sit back: job done."

The Conservatives brought in the 62-page bill following the murders of two Canadian soldiers just days apart last October by men whose motives were rooted in extremist thinking.

The legislation would give the Canadian Security Intelligence Service the ability to actively disrupt terror plots, make it easier for police to limit the movements of a suspect, expand no-fly list powers, crack down on extremist propaganda and dismantle barriers to exchanging security-related information.

Neither the new disruptive powers nor the information-sharing provisions apply to "lawful" advocacy, protest and dissent, but some critics say these elements of the bill could be used against aboriginal and environmental activists who protest outside the letter of the law.

Justice Minister Peter MacKay categorically rejected Palmater's view.

"Doing nothing is making terrorism win, and so it's incumbent upon any government to protect its population and to take actions to do so," MacKay said after question period.

"We believe this is consistent with what our allies have done."

During her testimony, Palmater recounted how she is already routinely tracked by federal agencies that keep tabs on her involvement in aboriginal issues.

Conservative MP Diane Ablonczy stressed that "jihadi terrorists have declared war on Canada," and she tried to dispel any notion the bill would be used to target legitimate dissent.

Fellow Conservative LaVar Payne dismissed concerns about the legislation's information-sharing provisions as "conspiracy theories."

The bill "isn't really about terrorism," but about preserving economic and power relations in Canada, Palmater said.

Citizens have worked too hard to create treaties, the Charter of Rights and Freedoms and international laws that protect basic human rights to toss it all away "because we wanted to protect some corporate economic interests," she added.

Her arguments were echoed by Grand Chief Stewart Phillip of the Union of British Columbia Indian Chiefs, who said the bill would dangerously expand powers of Canada's security agencies without making people any safer.

Phillip, who also called for the withdrawal of the legislation, accused the Harper government of retooling its policy-making efforts to foster natural-resource extraction.

He said the bill was about increasing the output of the Alberta oilsands and supporting the oil-pipeline agenda.

Former public servant Robert Morrison, who led a now-defunct information-sharing initiative at the Treasury Board before he retired, said a pilot project on border security persuaded him officials were not exchanging data to the degree they could.

The federal bill will support sharing in a manner consistent with charter and privacy rights, allowing officials to piece together disparate bits of information, he told MPs.

Intelligence historian Wesley Wark, who teaches at the University of Ottawa, said there are unanswered questions about the plan to give CSIS new disruption powers.

The bill contemplates allowing the spy service to use clandestine methods to derail plots -- from altering a website or cancelling an airline reservation or even more drastic actions.

CSIS already engages in some forms of disruption, but it's not clear if the spy service has implemented watchdog recommendations on using the tactic, Wark told the committee.

Disruption should be focused on Canadian suspects overseas under appropriate controls, he added.

The bill is missing greater accountability measures, does not address Canada's threat-assessment capabilities and fails to clarify the role of the government's electronic spy agency, the Communications Security Establishment, he said.

Wark believes the CSE will be "deeply engaged" by various provisions of the bill that will see it help other agencies collect information at home and abroad. Yet the legislation underpinning the organization has been in need of an update for many years, he said.