A prominent human-rights group says the Conservative government's anti-terrorism bill could be used to target environmental activists and aboriginal protesters.

In a brief made public Monday, Amnesty International Canada adds its voice to those who say the bill would go beyond genuine security threats to ensnare those who mount demonstrations that fall outside the strict letter of the law.

The Conservatives brought in the bill – which would significantly expand the Canadian Security Intelligence Service's mandate – following the murders of two Canadian soldiers last October.

Story continues below advertisement

The legislation would give CSIS the ability to disrupt terror plots, make it easier for police to limit the movements of a suspect, expand no-fly list powers, crack down on terrorist propaganda, and remove barriers to sharing security-related information.

The new disruptive powers do not apply to lawful advocacy, protest and dissent, but Amnesty fears they could be used against activists who protest without an official permit or despite a court order.

Canada must not slip into the pattern – seen elsewhere in the world – of leaving human rights behind in the name of protecting national security, Amnesty warns.

"It is absolutely vital that terrorist threats be addressed through measures that are in keeping with international human rights obligations," said Alex Neve, secretary general of Amnesty International Canada.

The House of Commons public safety committee plans to hear more than 50 witnesses on the bill during beginning Tuesday.

The bill and legislation tabled last fall dealing with CSIS source protection and foreign-spying powers amount to the most comprehensive reform of Canada's security laws since 2001, Amnesty notes.

CSIS has always been able to operate overseas to counter security threats to Canada.

Story continues below advertisement

However, long-planned legislation brought forward last October would give the spy service more latitude to obtain a court-ordered warrant authorizing security investigations abroad.

The amendment flows from court judgments that took issue with CSIS's powers to operate outside Canada – including a biting one by Federal Court Justice Richard Mosley that criticized CSIS for requesting warrants to track two Canadians with technical help from the Communications Security Establishment, Canada's electronic spy agency.

CSIS failed to disclose to Mosley that CSEC's foreign counterparts in the Five Eyes intelligence network could be called upon to help – something the judge called "a deliberate decision to keep the court in the dark about the scope and extent of the foreign collection efforts."

The legislation also tweaks the CSIS Act to prohibit the naming of individuals who might be involved in covert operations in the future.