OTTAWA - After months of running neck and neck in the polls, the Conservatives appear to have opened up a big lead over the slumping Liberals.

A Decima Research survey, released to The Canadian Press, put Tory support at 36 per cent nationally, back up to where the minority government was just over a year ago when it won power.

The Liberals polled 27 per cent, down from the 30 per cent they earned in the last election and even further from the mid-30s popularity they held shortly after Stephane Dion became leader in December.

The Green party jumped to 12 per cent, putting it in a virtual dead heat with the NDP, which polled 13 per cent.

Bloc Quebecois support in Quebec, meanwhile, dropped to 35 per cent -- down from nearly 50 per cent in the run-up to the January 2006 federal election. The Liberals were at 23 per cent and the Tories, 15.

With almost daily ruminations in the capital about a potential spring election, the latest polling numbers help focus attention on just whose interest an early election would serve.

"So far, it's probably safer to say that the biggest story has been that the Liberals did have a honeymoon after the leadership selection and the effect of that honeymoon has dissipated very significantly," said Decima CEO Bruce Anderson.

"It would be a mistake, though, not to note that the Conservatives have been slowly but surely increasing their support -- and increasing it particularly among urban voters, among female voters and in Ontario; three groups that they really needed to do better with."

The survey of more than 1,000 respondents, taken Feb. 22-26, suggests Liberals lost their long-time edge in Ontario, slipping to 32 per cent while the Tories surged to 40 per cent.

So there's virtually nothing in the Decima survey that would spur any of the opposition parties to bring down Prime Minister Stephen Harper's minority government, said Anderson.

The national numbers are considered accurate within plus or minus 3.1 per cent, 19 times in 20, while provincial margins of error are higher.

Three-week rolling averages of Decima's weekly data dampen the dramatic shift of fortunes, but nonetheless illustrate the point. Combining three separate surveys going back to Feb. 8, Tory support is 33 per cent, the Liberals have 30, the NDP 14 and the Greens 11.

In Ontario, the three February surveys average out to marginal 37-35 lead for the Liberals over the Conservatives, with the NDP at 16 per cent and the Greens at 11.

And in Quebec, the rolling averages put Bloc support at 38 per cent, followed by the Liberals at 23, the Tories at 16, the Greens at 10 and seven per cent for the NDP.

"They're not numbers that necessarily suggest a (Conservative) victory in an election is a slam dunk, let alone a majority victory," said Anderson.

The Decima numbers mirror a mid-February poll by Strategic Council that put the Conservatives ahead of the Liberals nationally 34-29.

The House of Commons begins a two-week break this weekend, and Dion will use the time to travel the country in an attempt to spread the Liberal message and bolster his party's fortunes.

Anderson said Dion needs to re-establish his environmental bona fides in the face of bleeding to the Greens.

Not only is the upstart party, which lacks any representation in the Commons, stealing support nationally from New Democrats, it is also eroding Liberal support in Ontario.

"The Green party is picking up a significant amount of support at the expense of the Liberal party," said Anderson, "and the Conservatives are improving their situation on environment issues."