As the House public safety committee prepares to wrap up witness testimony on the government's proposed anti-terror bill on Thursday, the New Democrats are getting set to propose amendments that would boost oversight powers and do more to combat radicalization.

The motion, which stands in the name of NDP house leader Peter Julian and could be debated in the House as early as Thursday, would allow the committee to consider amendments in two specific areas: to "ensure that the government works with Canadian communities to counter radicalization" and "enhance oversight of Canadian security and intelligence agencies."

The legislation goes to clause-by-clause review next week. Without such authorization, any amendments that go beyond the current scope of the bill would likely be deemed out of order during the review.

Liberal spokeswoman Kate Purchase says her party backs the bid to broaden the parameters, but without Conservative support, it will likely be defeated.

It's still not clear whether the government is open to changing the bill — or, for that matter, what amendments will be put forward by opposition members next week.

Liberal public safety critic Wayne Easter and rights and freedoms critic Irwin Cotler will present their party's proposed changes on Thursday.

MacKay open to amendments?

Speaking with reporters on Monday, Justice Minister Peter MacKay suggested that, rather than create a new oversight regime, "we could look at examining ways in which we can make the oversight bodies more effective, and be able to follow the information."

On Tuesday, he said it was up to the committee "to look at ways in which they might suggest improvements."

"We’ll await any recommendations that they make [and] await the outcome of that process."

Meanwhile, the House public safety committee continues its review of the proposed legislation this evening, when MPs are slated to hear from more expert witnesses.

Among those scheduled to testify today are representatives from the Canadian Bar Association.

Charter breach provision 'extremely troubling'

Earlier today, CBA president Michele Hollins told CBC News Network host Heather Hiscox the group is particularly concerned over the proposed provision to allow CSIS agents to ask the federal court to sign off on activities that could breach the Charter of Rights and Freedoms.

"The judicial warrants that appear in the CSIS portion of this legislation envision a situation where CSIS agents are going to knowingly commit a violation of the charter," Hollins said.

"They are then … authorized to go and ask a judge — who, of course, is herself charged with upholding the constitution and upholding the charter — to preauthorize a breach of the charter."

Such a scenario, she said, is "extremely troubling."

More witnesses

Hollins also agreed that environmental activists, First Nations organizations and other groups are right to fear that their protests could find themselves caught in the anti-terror dragnet as a result of the new provisions.

"The language appears to be drafted very purposefully broadly," she told CBC News.

As a result, Hollins said, it "carries with it the dangers of capturing any number of acts, communications, statements, events that are not a threat to national security, and one would not anticipate should be included."

Other witnesses appearing tonight include:

Council for Muslims Facing Tomorrow president Raheel Raza

Canadian Labour Congress president Hassan Yussuff

Mackenzie Institute general manager Andrew Marjoran and chair Brian Hay

Terrorism expert Thomas Quiggan

American Islamic Forum for Democracy president Zuhdi Jasser

Postal union opposes bill

Meanwhile, the Canadian Union of Postal Workers has added its name to the lengthening list of those worried at what they describe as the "overly sweeping reach" of the bill.

The union "knows what it is like to experience out-of-control state surveillance," Denis Lemelin said in a press release sent out on Wednesday morning.

The release notes that "in the early days of the union, a CSIS provocateur, Grant Bristow, was discovered to be working at a postal plant," and adds that the union's national office was "bugged by the RCMP" in the 1980s.

"In the 1990s, the union asked for its security files under the Access to Information Act, only to be denied the bulk of the records, deemed 'harmful to the defence of Canada,'" it continues.

"What was released revealed not only a massive surveillance operation on the daily activities of union members, but also collusion between the RCMP and Canada Post management."

Given that history, Lemelin believes the new laws "would make it all too easy to target ordinary working people or any marginalized group and label them 'terrorists'."

"We should accept no violations of our human rights and freedoms in the name of national security," he added.

Mozilla comes out against C-51

The bill is also drawing criticism from south of the border.

On Wednesday, Mozilla — the organization behind the Firefox browser — called C-51 "even more concerning" than the controversial Cybersecurity Information Sharing Act currently before the U.S. congress.

"C-51 is sweeping in scope, including granting Canadian intelligence agencies CSIS and CSE new authority for offensive online attacks, as well as allowing these agencies to obtain significant amounts of information held by the Canadian government," Mozilla internet policy manager Jochai Ben-Avie wrote in a post on the official Mozilla blog.

He warned that the "open-ended internal information-sharing exceptions" could leave Canadians wondering whether they can trust that personal data provided to the government will be used only for its original intended purpose.

"The bill further empowers CSIS to take unspecified and open-ended 'measures,' which may include the overt takedown of websites, attacks on Internet infrastructure, introduction of malware, and more, all without any judicial oversight," he added.

"These kinds of attacks on the integrity and availability of the Web make us all less secure."