As the House committee prepares to begin clause-by-clause review of government's anti-terror bill, Public Safety Minister Steven Blaney and Justice Minister Peter MacKay spent nearly an hour and a half taking questions on the legislation at the Senate national security committee on Monday afternoon.

Although the bill isn't expected to make it to the upper house until later this month, the Senate committee has already begun a pre-study of the content.

The proposed legislation would give the Canadian Security Intelligence Service more power to thwart suspected terrorist plots — not just gather information about them. It would also allow CSIS to violate the Charter of Rights and Freedoms with a judge's permission, expand the sharing of federal security information, broaden no-fly-list powers and create a new criminal offence of encouraging someone to carry out a terrorist attack.

The bill would also make it easier for the RCMP to obtain a peace bond to restrict the movements of suspects and extend the amount of time they can be kept in preventative detention.

Blaney and MacKay took advantage of the opportunity to counter some of the criticism the bill has elicited during its progress through the House, particularly the privacy implications of the enhanced information-sharing powers and the provision about judicial authorization for charter breaches.

Current privacy rules would apply: ministers

On the privacy issue, both ministers stressed that the existing Privacy Act would apply to the new powers, which would give the federal privacy commissioner the freedom to investigate — and even initiate — complaints.

"We expect that any department… will proceed as they ought to do by a privacy assessment, in accordance with the privacy commissioner's recommendation and guidance," Blaney said in his opening statement.

As for the more complex issue of asking federal judges to sign off on potential Charter breaches, Blaney pointed out that it is already the role of judges to issue warrants.

"They've been doing it for years," he noted.

"I invite anyone making a statement — I would refer them to the Criminal Code, Article 25, if they have any doubts."

The section in question makes no reference to Charter breaches, but lays out the process for obtaining a standard warrant as part of a criminal investigation.

Broader powers for CSIS means more power for SIRC: Blaney

Meanwhile, Senate Liberal Grant Mitchell wondered why the government hadn't concurred with the calls for additional oversight, which, he suggested, could have gone a long way to "sell the bill" by alleviating concerns over civil liberties and rights.

"It's an odd oversight that you didn't get to oversight in this bill," he contended.

In response, both MacKay and Blaney lauded the existing regime, and particularly the Security Intelligence Review Committee charged with reviewing CSIS activities, which Blaney averred, once again, is the envy of the world.

"By broadening the power of CSIS, we are … giving more power to [SIRC]," he argued.

Amending C-51 'mission impossible': May

Earlier Monday, Green Party Leader Elizabeth May made it clear the "less than a handful" of government-backed amendments expected to be made to proposed new anti-terror laws won't be sufficient to get her to support what she describes as a "deeply flawed" bill.

But she believes it is "very significant" that the government felt compelled to bring forward any amendments at all.

"The last time this happened was on the so-called Fair Elections Act," she told reporters at a press conference on Monday morning. "It's encouraging that public pressure is working.

"It's proof that, though they didn't listen to witnesses, they're watching the polls, and watching support for this bad bill slip away … under their feet."

When Prime Minister Stephen Harper decides any "product of PMO ...(is) less than 100 per cent perfection," she said, that's progress.

"But do those amendments satisfy my concerns that this is dangerous legislation? No."

Green Party Leader Elizabeth May and Green MP Bruce Hyer present their party's proposed amendments to the government's anti-terror bill. (CBC)

That's why she and her lone caucus colleague, Bruce Hyer, intend to put forward five dozen amendments when the House of Commons public safety committee begins examining the bill clause-by-clause on Tuesday.

Expanded spy powers 'most dangerous': May

"Trying to fix this bill is mission impossible," May said before outlining her party's proposed changes.

"But it is important to make substantive, thoughtful amendments where possible."

To that end, she and Hyer will present the committee with amendments addressing a wide variety of concerns, from the "undue burden" the new provisions will put on the airline industry to requiring CSIS inform the RCMP of any planned covert actions.

In May's view, it is the section expanding the spy agency's powers that is "the most dangerous" aspect of the bill.

"The activities of the secret police will rarely connect themselves in a way that will allow them to go to court to be challenged there," she pointed out.

"Almost everything else in this bill is going to eventually end up before the courts, and go to the Supreme Court, and the bad parts will be judged unconstitutional," she predicted.

"But this section ... says to CSIS agents, you can go to a judge and get permission to violate the charter."

That, she said, is unheard of, which is why she's proposing CSIS should have to let the RCMP know what it has planned.

Despite the enhanced information-sharing provisions in the bill — which are also targeted for amendment by the Green duo — May pointed out that there is "no communication required" between law enforcement and departmental agencies.

Her proposal would at least ensure the RCMP is in the loop when CSIS is plotting out how to employ its new powers to disrupt potential threats.

Although neither May nor Hyer sit on the committee, they will be permitted to present — but not vote on — their amendments during clause-by-clause review Tuesday.

The NDP and Liberals have also called for changes to the legislation to protect civil liberties and improve oversight of security agencies.

But while May shares the other opposition parties' concerns over the lack of new oversight measures, she predicted any amendments to address that gap would be ruled out of order, as it would go beyond the scope of the bill.