OTTAWA–Gun-control advocates say they are horrified and fearful that Canada's long-gun firearms registry is on the verge this week of being scrapped because the Conservatives may have enough support from the opposition to kill it.

Wendy Cukier, president of the Coalition for Gun Control, says her organization has been monitoring the progress of a Conservative private member's bill to abolish the registry and is now bracing for it to clear an important vote in the Commons on Wednesday.

"It is astonishing, just a few months after the opposition parties voted for a Bloc Québécois motion that reiterated support for the firearms registry and against efforts to repeal it, that many of the same MPs will support this Conservative bill," Cukier said Sunday.

"It not only eliminates the need to register rifles and shotguns but requires that the information contained on seven million registered guns be destroyed."

Cukier's fears are confirmed by NDP MP and justice critic Joe Comartin, who believes that it's almost an "inevitability" that the private member's bill known as Bill C-391, put forward by Manitoba Conservative MP Candice Hoeppner (Portage-Lisgar), will have enough support from the opposition to squeak through approval in principle at second reading.

Liberal MP Mark Holland (Ajax-Pickering) said he's not ready to concede defeat yet on killing the bill, but he acknowledged it's going to be tight and it means that a lot of pressure is going to be placed on individual Liberal MPs over the next few days to block the legislation.

"This is deeply concerning. The implications of dismantling the long-gun registry are very serious," Holland said, noting Toronto Police Chief Bill Blair was only last week hailing the registry as instrumental in the seizure of a 58 —guns. All the Conservatives need are between seven to 10 MPs from the opposition benches to support the legislation, and Comartin says he's reasonably certain Conservatives have secured that number from his own caucus and from Liberal ranks.

Wednesday's vote isn't a death warrant for the registry – it still has to be examined by a Commons committee, pass again in the Commons and then in the Senate.

But if the bill passes on Wednesday, it means the registry's abolition will have been approved in principle in this minority Parliament and will undoubtedly be hailed as a victory for foes of the gun-registration system, which was put in place after furious debate in the mid-1990s under former prime minister Jean Chrétien.

The key to this bill's potential success is that it is not a piece of government legislation, in which case NDP Leader Jack Layton and Liberal Leader Michael Ignatieff could insist that all MPs vote against it. But private members' bills are free votes.