OTTAWA - The leaders of the federal Liberals and NDP are keeping their powder dry on Prime Minister Stephen Harper's call for a free vote on scrapping the federal long gun registry.

Liberal chief Michael Ignatieff, in an interview Sunday on CTV's Question Period, said he wants to know more about a bill that would do away with registration requirements for hunting rifles and shotguns before taking a firm position on the measure.

"I don't know quite what I'm being asked to vote on, and I'm not going to commit myself until I've seen the fine print," said Ignatieff.

He acknowledged, however, that there's a distinction between sport shooters and those who use firearms - mostly handguns - as part of a criminal lifestyle.

"No sensible Canadian thinks the problem is the shotgun on the barn door," said the Liberal leader. "No sensible Canadian thinks the problem is the target shooter or the legitimate licensed gun owner.

"The problem is those handguns."

At issue is a bill sponsored by Conservative backbencher Garry Breitkreuz to dismantle the long gun registry that has irritated many farmers, hunters and target shooters.

But critics say the bill, as currently drafted, goes far beyond that goal and would loosen licensing, registration and transport rules for handguns and other semi-automatic weapons as well as for sporting firearms.

Breitkreuz has promised to revise the bill to delete the sections that have drawn the most criticism, but many of his opponents remain skeptical.

NDP Leader Jack Layton, speaking Sunday after a party meeting in Ottawa, said the bill as now worded would "make our streets more dangerous."

"They didn't think it through, it's not right, and it shows they really don't have in mind dealing with gun crime the way most Canadians do."

Nevertheless, Layton didn't shut the door on the possibility of a free vote, saying it's "not a practice" of the NDP to whip its MPs to toe the party line on private member's bills.

At least one NDP backbencher, John Rafferty from the northern Ontario riding of Thunder Bay-Rainy River, has publicly campaigned for abolition of the long gun registry. A party source said there may be a "handful" of other New Democrats with similar views, though Layton insisted he hasn't done a head count.

The Tories are also targeting Liberals from small towns and rural areas in the hope of winning them over.

Former public safety minister Stockwell Day tabled two bills before the last election aimed at abolishing the long gun registry, but both died in the face of concerted opposition from the Liberals, New Democrats and Bloc Quebecois.

Breitkreuz and like-minded backbenchers think a private member's bill could have a better chance because there's a tradition of relaxing party discipline on such measures and letting MPs vote their consciences, or the wishes of their constituents.

Harper made it clear he's backing that strategy in a speech Saturday to the Ontario Federation of Anglers and Hunters.

"We are looking to unite a majority of MPs in repealing the long gun registry," said the prime minister.

"The leaders of the opposition parties continue to be against this. But there are MPs in all these parties that know what we know, that law-abiding hunters and farmers are not part of the crime problem.

"I challenge you to press these MPs to follow their consciences."

Wendy Cukier, head of the Coalition for Gun Control, said it's obvious the Breitkreuz bill is a government-supported one despite its official classification as a private member's bill.

She also took issue with the distinction drawn between long guns and handguns in an effort to gather public support for the bill.

"Rifles and shotguns kill just as dead as handguns," said Cukier. "A rifle or a shotgun in the wrong hands is just as deadly. We need controls over all firearms."

The Tories, who hold 143 seats in the 308-seat Commons, would need 11 opposition MPs to side with them to ensure victory in the lower house. They would also have to find a way to get the bill through the Liberal-dominated Senate.