Canada's access to information and privacy watchdogs are calling on the government to make sure that any move to boost the powers of police and intelligence agencies will be evidence-based and have effective oversight mechanisms to ensure "fundamental rights and freedoms" are upheld.

"We acknowledge that security is essential to maintaining our democratic rights," the statement notes.

"At the same time, the response to such events must be measured and proportionate, and crafted so as to preserve our democratic values."

To that end, they want to see the government "adopt an evidence-based approach" in considering any boost to existing intelligence and police powers, and to ensure that any new measures include "effective oversight."

They also want to see an "open and transparent dialogue" with Canadians "on whether new measures are required, and if so, on their nature, scope, and impact on rights and freedoms."

"At the end of the day, what we're advocating is that we have sufficient information, so that we can have open dialogue, and that we have proper oversight of any [organization] that actually is enforcing the law, or enforcing national security measures, such that we can hold the government to account," federal Information Commissioner Suzanne Legault told reporters.

"We need to know whether the government is acting responsibly, and in order to do that, we need to have access to the information to have a proper discussion [and] properly evaluate the measures that are being put forward."

Federal, provincial and territorial commissioners and ombudsmen are in Ottawa for their annual meeting, which begins today and continues on Thursday.

Harper praises CSIS for 'unfailing dedication to the law'

Speaking in the House on Wednesday afternoon, Prime Minister Stephen Harper defended the existing oversight regime.

In response to a question from NDP Leader Tom Mulcair, he praised CSIS for its efforts to protect Canadians.

"Not only does it do important work, but repeatedly, over a long period of time, the agencies that are in place to provide oversight for that work have reported the agency's unfailing dedication to the law, and to the respect and protection of Canadians," he noted.

Harper also seemed to dismiss Liberal Leader Justin Trudeau's call for an all-party national security oversight committee.

"Under successive governments of different political stripes, the government has long had a system of effective oversight of CSIS and our security agencies," he said.

"While … we always recognize the certain risks that exist, I do not think we should start from the assumption that everything our police and security agencies do are somehow a threat to the rights of Canadians."

In fact, he continued, "more often than not, security and rights find themselves on the same side of the ledger."

"Canadians do not have effective rights unless we can ensure their security, and that is what we intend to do."

'Arar +10' conference

Elsewhere in Ottawa, a special symposium spent the day exploring the shifting balance between national security and human rights a decade after the launch of a judicial inquiry into the treatment of Maher Arar.

Dubbed "Arar +10," the conference is being hosted by the University of Ottawa Centre for International Policy Studies, along with Amnesty International, the International Civil Liberties Monitoring Group and the Human Rights Research and Education Centre.

Among the events on Wednesday's agenda: an "unprecedented keynote lunchtime panel" with the three judges who have presided over judicial inquiries related to national security in the last 10 years:

Former Supreme Court justice Frank Iacobucci (Internal Inquiry into the Actions of Canadian Officials in Relation to Abdullah Almalki, Ahmad Abou-Elmaati and Muayyed Nureddin)

Former Supreme Court justice John Major (Commission of Inquiry into the Investigation of the Bombing of Air India Flight 182)

Former Ontario Court of Appeal justice Dennis O’Connor (Commission of Inquiry into the Actions of Canadian Officials in Relation to Maher Arar)

On Monday, Public Safety Minister Steven Blaney tabled a bill that would expand the powers of the Canadian Security Intelligence Service (CSIS) to monitor and track suspected terrorists and provide increased protection for confidential sources.

It would also give the agency more leeway to operate outside Canada, including sharing intelligence with members of the so-called "Five Eyes" countries: Canada, the United States, the United Kingdom, Australia and New Zealand.

Meanwhile, retired House of Commons law clerk Rob Walsh took to Twitter on Wednesday morning to share his concerns that calls for new police powers may be an overreaction.

"Violent, deranged loners [are] not new," he pointed out.

"Let us not use lone violence as an excuse for unwarranted anti-civil rights and anti-privacy initiatives."