OTTAWA - Conservative misfortunes don't appear to be helping the Liberal opposition, suggests a new poll that has both federal parties the preferred choice of fewer than one in three Canadians.

The Canadian Press Harris-Decima survey placed the two major parties in a statistical dead heat, with the Tories nominally ahead of the Liberals 31-30.

Relative to the last Harris-Decima poll, the Tories are down four percentage points and the Liberals are down three.

"I think both parties have to look at each other right now and say the evidence is that their opponents are their best advantage,'' said Harris-Decima president Bruce Anderson.

"They're the thing that gives them hope for the future in the absence of being able to create any momentum independently.''

While the Tories and Liberals appeared stalled, the NDP at 17 per cent and the Bloc Quebecois at eight per cent nationally were not big beneficiaries.

Instead, the Green party with 13 per cent nationally and an astonishing 18 per cent in Ontario became what Anderson called the "parking phenomenon'' for disillusioned voters.

The telephone poll of more than 1,000 respondents was taken over the last weekend and is considered accurate within plus or minus 3.1 percentage points, 19 times in 20. Regional breakdowns have larger margins of error.

The survey followed the release of the 2008-09 federal budget last week, and began just after news broke of the Chuck Cadman bribery allegations and in the midst of a war of words between Finance Minister Jim Flaherty and Ontario Premier Dalton McGuinty.

Anderson suggests the latter two issues are hurting Tory fortunes, while the budget did little to boost the governing party.

It's part of pattern the pollster has seen since at least last fall, when Prime Minister Stephen Harper reset the agenda by delivering a new speech from the throne with fresh government priorities, then a tax-cutting economic update.

"At each interval, when it looked like (the Tories) were getting some kind of daylight and able to talk about their agenda, they've been put off stride,'' said Anderson.

The Cadman controversy involves allegations, relayed by the dying Independent MP to his wife and family in 2005, that he'd been offered a $1 million life insurance policy by Conservative operatives in return for his vote against a Liberal budget.

Flaherty has been vigorously sparring with McGuinty over Ontario's corporate tax rates, and a Harris-Decima poll last week suggested the Ontario premier enjoyed a wide advantage in the public relations battle.

"I think that's an issue that probably has as much traction right now as the Cadman item,'' said Anderson.

For the Liberals under Leader Stephane Dion, said the pollster, the political landscape "continues to look like it holds promise, but without much evidence they can capitalize on it.''

Ontario support for the Liberals stood at 34 per cent, with the Tories at 30, the Greens at 18 and the New Democrats at 17 per cent.

In Quebec, the survey had the Bloc leading with 33 per cent, followed by the Liberals at 25, the Conservatives at 20, the NDP at 13 and the Greens at seven.