NDP Leader Jack Layton is allowing MPs to vote as they choose on an upcoming gun registry motion. (Andrew Vaughan/Canadian Press)

The embattled long-gun registry received support on Monday from another New Democrat MP.

Malcolm Allen, who represents the Ontario riding of Welland, said Monday he will join three other NDP colleagues in switching their votes when Tory backbencher Candice Hoeppner's private member's bill to repeal the registry comes to a vote in Parliament.

Allen told reporters at the NDP caucus meeting in Regina that people in his riding have told him they want to keep the registry.

While the NDP were discussing the issue during the second of three days of meetings, the Conservatives launched a series of ads on Monday targeting both Liberals and New Democrats who voted in the past to scrap the registry.

But with the Liberals and the Bloc Quebecois poised to vote on Sept. 22 to halt Hoeppner's bill, and the Conservatives set to vote the other way, the fate of the registry lies with the NDP.

Six NDP MPs who previously voted in favour of Hoeppner's bill have said they will not change their vote to scrap the registry.

Allen's switch brings the number of MPs who have declared their support or opposition to Hoeppner's bill to a 151-151 tie.

Manitoba NDP MP Niki Ashton (Churchill) has yet to indicate how she will vote. And NDP MP Carol Hughes (Algoma-Manitoulin-Kapuskasing), has said she will not vote to scrap Hoeppner's bill on Sept. 22, but wouldn't say what side she would choose if the bill reaches a vote on third reading.

Layton seeks compromise

NDP Leader Jack Layton, who is allowing MPs to vote as they choose, said he hopes a compromise can be reached that will bring about changes to the registry without seeing it scrapped.

"Let's see if we can't have a registry that functions well, that people feel they can participate in without feeling like a criminal, and then police will have the public safety tool they need," Layton said Sunday, at the start of the caucus meeting.

Layton has suggested his party could introduce legislation in the House to make a first-time failure to register a firearm a non-criminal ticketing offence and to waive fees for new licences. The proposed legislation would respect aboriginal treaty rights and allow municipalities to ban handguns, he has said.

NDP in losing position over registry: pollster

Pollster Nik Nanos of Nanos research said whatever the NDP decides, the party is in a losing position with voters. He said supporters in urban centres could be dismayed by the push to scrap the registry, and could move to support the Liberals. NDP supporters in the West are more likely to want to see the registry gone, and may move over to the Conservatives.

"I think Jack Layton is going to lose, regardless," Nanos said.

But NDP MP Joe Comartin (Windsor) said he doesn't believe it will be that easy to uproot New Democrats over the issue.

"Every analysis is that this is a vote determiner for less than one per cent of the voting public and that doesn't have enough of an impact, I don't think, in any of our ridings," he said. "Every one of our ridings were won by more than one per cent."

In the most recent vote on Hoeppner's bill during the last parliamentary session, 12 NDP MPs joined eight Liberals and all 144 Conservatives to ensure it passed a second reading 164 to 137.

The situation will change somewhat for the Sept. 22 vote on a Liberal motion calling on the House to no longer consider Hoeppner's bill. Liberal Leader Michael Ignatieff has called for a whipped vote, and the party says all 77 Liberals will vote to kill the bill.

With files from The Canadian Press