The Liberal government's new security bill adds torture, detention and serious destruction of property that would endanger a life to the list of things Canada's spy agency cannot do when disrupting terror plots.

The legislation introduced this week retains controversial derailment powers for the Canadian Security Intelligence Service, but the Liberal government says various amendments will provide safeguards and ensure public confidence.

The Conservatives gave CSIS explicit authority to derail security threats, not just collect information about them, in legislation passed two years ago.

It barred the spy service from threat-disruption measures that involved obstructing justice, killing someone, committing sexual abuse or otherwise causing bodily harm.

However, many expressed concern the provisions permitted disruption activities that could violate the Constitution.

The Liberal legislation requires CSIS to seek a warrant for any threat reduction measure that would "limit" a right or freedom protected by the Charter of Rights and Freedoms and it clarifies that a warrant can be issued only if a judge is satisfied the measure complies with the charter.

In addition to expanding the list of forbidden disruption tactics, the bill spells out the things CSIS can do to derail a threat. These include destroying equipment, forging documents, diverting a financial transaction, interfering with a person's movements and impersonating someone in order to carry out such acts.

In the House of Commons, Conservative Leader Andrew Scheer accused Prime Minister Justin Trudeau of trying to water down national security laws by reining in the disruption powers.

"Several of our European allies are now dealing with the threat of terrorism on literally a weekly basis and the fact is that Canada is not and will not be immune to this threat," Scheer said.

"Will the prime minister specifically be open to restoring the proactive ability for our national security agencies to disrupt terrorist threats when mere minutes matter?

Trudeau said the government was open to suggestions, adding that no one in the Commons takes the responsibility of public safety lightly. "I look forward to robust discussions with all parties in the House, all members in the House, hearing from experts as we move forward on getting that balance right."

The 150-page Liberal bill modifies other contentious elements of the 2015 Conservative bill, charts fresh paths for Canada's security services in data analysis and cyberspace and beefs up accountability through a new super-watchdog.

The NDP says the government has not gone far enough in pulling back on the Conservative anti-terror measures.

The Ottawa-based International Civil Liberties Monitoring Group said while the Liberal bill is a welcome break with the past, it fails to move Canada in a bold new direction that would place liberties and human rights at the heart of the country's security laws.

The group pointed to provisions in the Conservative legislation that increased no-fly list powers and made it easier for federal agencies to share personal information. These measures, like the CSIS disruption powers, would be curbed somewhat but not eliminated by the Liberal makeover.

The proposed super-watchdog to oversee a range of federal agencies with security responsibilities would be complemented by a new national security committee of MPs and senators who are able to see classified information.

The Senate has passed the enabling legislation for the committee, and Public Safety Minister Ralph Goodale said Wednesday he hopes to see the members in place quickly.

"There is work for this committee to do."

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