Fresh from limiting the parliamentary debate on its proposed anti-terror law, the government is now resisting opposition calls for an extensive review of Bill C-51 by the Commons committee on public safety and national security.

"This bill is strongly supported by Canadians," Stephen Harper argued this week during Question Period, "and I encourage the committee to study it as quickly as possible in order to adopt these measures to help Canadian security during the life of this Parliament."

What the prime minister bases his judgment of public support on isn't clear, though one opinion poll has suggested four out of five Canadians are in favour of giving Canada's spy agency and police broad new powers.

But public support, no matter how it's measured, is no substitute for public scrutiny.

The government's bill proposes to give Canada's spy agency broad new powers to disrupt suspected terrorist plots, to allow government departments to share private information more widely, and to allow suspects to be detained without charge for longer periods.

But critics say that these new powers, and overly broad definitions in the proposed law, represent a threat to Canadians' rights, without any commensurate increase in parliamentary or third-party oversight.

An election winner?

The Conservatives, on the other hand, say Canada has to respond to the October attacks in Canada that killed two Canadian soldiers, and to view these incidents as part of a trend that has seen brazen attacks in Paris and Copenhagen, and the arrest Thursday of alleged ISIS conspirators in New York City.

But that's only one of the motives. The party also considers public security a winning issue for them heading into an election, so much so that the government is determined to push this bill through with a minimum of parliamentary scrutiny and review.

As CBC News reported on Wednesday, the government is offering just three days for the committee to hear from witnesses, with one of those days devoted exclusively to questioning Public Safety Minister Steven Blaney and department officials.

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NDP Leader Tom Mulcair has criticized Bill C-51 for vague wording, which he says leaves the door open to spying on political opponents. (THE CANADIAN PRESS/Sean Kilpatrick)

The New Democrats and Liberals want much more time for witnesses. And will press their case again today when the committee meets to arrange a schedule.

"We're talking about the most significant changes to security legislation in this country since 2001," NDP Leader Tom Mulcair told reporters on Wednesday.

"Critical flaws are being revealed by security experts across the country every single day. It is reckless and irresponsible to ram it through without a full and proper study."

For the Conservatives, more witnesses equates to more criticism, and the possibility that the public support Harper talked about might begin to erode.

Getting it right

The alternative view is that the more public scrutiny, the more likely the government is to get a significant piece of this legislation right, which is to ensure that the appropriate balance is struck between security and individual liberties.

And there are no shortage of examples to support that view.

The most obvious is the 2001 review of the original anti-terrorism law introduced after the 9/11 attacks by the then Liberal government of Jean Chretien.

The Commons justice committee met 19 times between Oct. 18 and Nov. 26, 2001 to review the bill. A special committee of the Senate began parallel hearings, wrapping up on Dec. 6.

Both committees met twice-daily at one point to ensure the politicians — and public — heard from as many witnesses as possible.

Wayne MacKay, a constitutional law professor at Dalhousie University, appeared before both committees in 2001. He says the extensive testimony helped the government of the day refine the legislation.

"The more alternative views you hear, the better the legislation will be," MacKay said in an interview Wednesday. "This is another very significant piece of legislation and it's worthy of a detailed review."

Harper LNG

With an election coming, the Canadian flag will be in demand. Here, Prime Minister Stephen Harper makes an announcement regarding tax cuts in Surrey, B.C., earlier this month. (The Canadian Press)

Don Stuart is a criminal law professor at Queen's University in Kingston. He also appeared before both committees in 2001, and says the Conservatives' approach to its anti-terror bill speaks more to political imperatives than security needs.

"The longer you go at committee, the more you hear opposing voices."

Lessons from the past

Stuart says there are elements of Bill C-51 that he believes are redundant, such as the new offence of promoting terrorism, or too vague, including the definition of terrorist activity.

In 2001, the Liberals accepted amendments to impose a five-year limit on the extraordinary new powers of preventative arrest and investigative hearings.

That bill, in its final form, withstood judicial scrutiny far better than either the U.S. Patriot Act or Britain's Anti-Terrorism, Crime and Security Act 2001.

This time, though, the Conservatives are showing no similar willingness to entertain amendments, even though that kind of obstinance has caused them political embarrassment before.

In 2011, the government tried to introduce a series of amendments to a mammoth crime bill at the last moment, amendments their own MPs had voted down earlier at committee simply because they had been proposed by Liberal MP Irwin Cotler.

It turned out the government actually agreed with Cotler's efforts and, proving imitation is the least sincere form of legislation, they copied nearly word for word Cotler's proposals to strengthen the right of victims to sue foreign states that supported or committed terrorist acts.

Liberal Leader Justin Trudeau

Here, Liberal Leader Justin Trudeau delivers a speech during an event in Mississauga, Ont., on Feb. 15. (Chris Young/The Canadian Press)

It didn’t work. The government's amendments were ruled out of order by House Speaker Andrew Scheer because they came too late in the legislative process.

In the end, the bill had to be amended in the Senate, and ended up mirroring what Cotler had proposed much earlier.

It's unlikely the Conservatives will now apply these past lessons as they push ahead with Bill C-51.

As the prime minister said, the goal is to have the new security measures in place before the House rises in June. Alongside a campaign message firmly embedded in the minds of voters before they head to the polls in October.