Among the questions it raises, said the NDP's Paul Dewar, is whether the new powers it proposes for security agencies are the best way to handle the threat of terrorism.
And meanwhile, asked the Liberals' Wayne Easter, what about the tools that are already in the arsenals of Canada's security agencies, yet remain unused?
But aside from the legislative elements of the bill, opposition parties are also carefully manoeuvring around it for political reasons, mindful that any quick move to contradict it could wind up with them being cast by the Conservatives as being soft on terror.
Both stressed the reality of the terrorist threat and the need for Parliament to ensure Canadians are as safe as possible.
Here is some of what they and other observers had to say:
New Democratic Party Foreign Affairs critic Dewar.
"Everyone in Canada is united in our determination to keep this land strong and free. From time to time we will disagree on how to achieve this goal but no matter what differences we may have, we believe all parliamentarians must approach this complex issue with the respect and dignity it deserves and we know that every member of Parliament is committed to the safety and security of all Canadians."
On the bill itself:
"We are concerned Conservatives have steadily given CSIS more powers while ignoring calls from experts and commissions of inquiry that our intelligence and security agencies also need better oversight.
"We are also concerned about the cuts Conservatives have made to the police, intelligence and broader security agencies in recent years. Unfortunately, all too often in the past we've seen the government playing politics with these issues."
Liberal Public Safety Critic Easter:
"We are supportive of all reasonable measures that will keep the public safe in Canada and we understand that in order to fight terrorism that police agencies and security agencies need the tools to keep pace with the times so they can challenge those that would do Canadians harm out there."
On the new measures:
"We've been expressing to the government, even asked Commissioner Paulson of the RCMP why some of those authorities that are already in place have not been used to the extent that we believe they could have been to arrest and detain those that might want to do Canadians harm. In terms of the additional powers that are in this legislation, as I indicated we will be reviewing it, see how far they go and question the various authorities on why what's in place hasn't been used and are these additional powers absolutely necessary for the agencies to do their job."
The British Columbia Civil Liberties Association, on the elements of the bill which give police greater powers to go after terrorist propaganda online:
"Criminalizing people's words and thoughts is misguided and won't make Canadians any safer. We will be less free, less democratic and less likely to know who to keep an eye on. This new law will impose a broad chill on legitimate political speech without enhancing public safety, and is likely unconstitutional." — Micheal Vonn, policy director of the British Columbia Civil Liberties' Association.
Susheel Gupta, whose mother died in the Air India terrorist attack:
"We're very pleased to see any laws that thwart terrorism. We want to ensure that no other Canadians suffer as we have."
Privacy commissioner Daniel Therrien:
"This act would seemingly allow departments and agencies to share the personal information of all individuals, including ordinary Canadians who may not be suspected of terrorist activities, for the purpose of detecting and identifying new security threats. It is not clear that this would be a proportional measure that respects the privacy rights of Canadians. ... I am also concerned that the proposed changes to information sharing authorities are not accompanied by measures to fill gaps in the national security oversight regime."
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