Three former government watchdogs appeared on a shuttered Parliament Hill Tuesday, to voice concerns over the treatment of civilian oversight bodies by the Conservative government.

The group included Peter Tinsley, who headed the Military Police Complaints Commission, Paul Kennedy, former chair of the RCMP’s public complaints commission and Linda Keen, ex-president of Canada’s nuclear safety regulator.

Keen, who was fired by the Conservatives, said that federal watchdogs are "under attack" by the government. As a result, acting commissioners -- who are supposed to be independent -- fear they’ll lose their jobs if they are too critical, she said.

Kennedy, whose tenure with the RCMP watchdog expired in December and was not renewed, told a press conference that he’s concerned the Tories are not serious about letting the RCMP’s 90-person complaints commission do its job.

He raised questions about the qualifications of his replacement, Ian McPhail, a lawyer who specializes in wills and real estate.

“I think in this particular case there will be significant challenges trying to have a credible presence with the Canadian public, and more importantly with senior members of the RCMP,†Kennedy said, suggesting that a background in criminal law is needed to run the commission effectively.

McPhail responded in a statement to Â鶹´«Ã½â€™ Power Play.

“My predecessor has left me with an extremely effective, well-run organization,†McPhail said. “I’ve been given a one-year mandate to ensure that the fine work of the commission continues. This is exactly what I’ll do.â€

Tinsley had been looking into the Afghan detainee abuse scandal when the decision not to renew his tenure was taken. He said he wasn’t given a reason as to why the government felt he should be replaced.

“We’re dealing in an environment where the exercise of discretion is pretty much unconstrained and doesn’t have to be explained,†Tinsley said.

“Discretion is part of our system and it’s been well used. But it’s got to be used in a principled fashion… in an open and transparent fashion that results in merit-based appointments,†he added

Earlier in the day, the trio of former watchdogs spoke at a meeting organized by the federal Liberals to discuss governance issues. The party is holding a series of round-table meetings this week in Ottawa, although Prime Minister Stephen Harper has prorogued Parliament until early March.

At the press conference that followed the meeting, Liberal Leader Michael Ignatieff referred to the former watchdogs as “impartial public servants†who are “independent of politics.â€

“The current government has tried to shut down the inquiry commission on military police. They have made the independent commission’s work on the RCMP nearly impossible,†Ignatieff said in French.

“This is part of a systematic approach of refusing respect for the independence of these organizations.â€

The Liberal leader called civilian oversight “crucial to the freedom of our country and the good functioning of our democratic system,†and promised to strengthen such bodies if the Liberals are eventually elected to run Parliament.

“We want Canadians to understand the importance we attach to these free and independent institutions, and to the functioning of our Parliament,†he said.

On Tuesday afternoon, Conservative MP Andrew Saxton said the Grits aren’t credible when it comes to accountability.

“The Liberals are not the ones to be lecturing us, or anybody for that matter, on governance,†Saxton said on Power Play, citing the federal sponsorship scandal.

“It’s our government that brought in the federal accountability act,†he said.

With files from The Canadian Press