OTTAWA -- Families of victims and witnesses to the 1989 Montreal massacre say Canada's hard-won gun control laws are being whittled away -- and no one seems ready, or even allowed, to talk about it.

Advocates of gun control say this week's shooting death of an Edmonton police officer illustrates the chill on discussing gun violence and public policy -- even as the Conservatives rush through another firearms bill that critics say weakens gun control.

In the wake of Monday's shooting, Edmonton Mayor Don Iveson suggested the elimination of the federal long-run registry in 2012 may be a factor in numerous altercations between police and armed assailants.

Justice Minister Peter MacKay blasted Iveson's comments as "absurd," "ill-timed" and "in poor taste," -- forcing an apology and retraction from the mayor.

On the same day, federal Public Safety Minister Steven Blaney labelled the Edmonton gunman a "right-wing extremist" and said the Harper government's new anti-terrorism bill would prevent such tragedies.

"It's in poor taste when we talk about gun control, but it's never in poor taste when we talk about terrorism or the things that are on the government's agenda," Heidi Rathjen, a witness to the shooting deaths of 14 women at Montreal's Ecole Polytechnique, said Thursday at a news conference on Parliament Hill.

She accused Conservative politicians and the gun lobby of using "intimidation tactics" to silence gun-control advocates and a complacent media -- leaving a complete absence of debate over firearms legislation.

No one seems curious, said Rathjen, about the three legally owned assault rifles in the possession of Justin Bourque, who gunned down three Mounties in Moncton last year. Nor has there been much talk about the provenance of the old hunting rifle used in last October's deadly Ottawa attack -- which Rathjen noted "was enough to paralyze all of Parliament and downtown Ottawa."

She was joined by Jim Edward and Suzanne Laplante-Edward, whose daughter Anne-Marie died in the 1989 massacre and who have lobbied for tougher gun laws ever since.

"Twenty-five years! What am I doing here today, I wonder?" said an emotional Laplante-Edward. "The Conservative government came and they destroyed everything, everything."

The latest police shooting and the imminent passage of Bill C-42, dubbed the Common Sense Firearms Licensing Act, spurred their intervention.

Blaney told a Senate committee earlier this week that C-42 "is actually the first substantive change to the firearms licensing regime since it was brought in 20 years ago."

He said the multi-faceted bill will increase public safety while streamlining paperwork and showing respect to the firearms community.

On Thursday, the committee heard from Rathjen and Wendy Cukier, president of the Coalition for Gun Control, who disputed Blaney's assessment.

Rathjen pointed out that neither the House of Commons committee nor the senators studying Bill C-42 heard from police associations, public health authorities, suicide prevention groups or women's shelters.

"This is disgraceful," she said, asserting that voting parliamentarians and the wider public remain in the dark about the bill's many provisions.

The legislation relaxes the rules on the transport of restricted firearms such as handguns and assault rifles, simplifies the licensing system by combining two types of firearms licences into one and gives politicians the power to override the RCMP's classification of semi-automatic weapons.

It also requires mandatory gun training for all licensees and imposes an automatic lifetime prohibition on firearms ownership by those convicted of domestic assaults.