Prime Minister Stephen Harper speaks at the end of the G20 Summit in London earlier this month. A new EKOS poll suggests public support for his Conservative party is slipping. (Kirsty Wigglesworth/Associated Press)

Fortunes have shifted substantially for Stephen Harper's Conservatives since December, with Michael Ignatieff's Liberals enjoying an upsurge, says a new poll from EKOS released exclusively to CBC News.

Asked which party they would support if an election were held tomorrow, 36.7 opted for the Liberals while 30.2 per cent chose the Conservatives. About 15.5 per cent supported the NDP, while the Green party was the choice of 8.1 per cent and the Bloc Québécois was backed by 9.4 per cent.

The survey was conducted using a hybrid internet-telephone research panel between April 8 and 13, and involved a random sample of 1,587 Canadians. It has a margin of error of plus or minus 2.5 per cent, 19 times out of 20.

A similar poll question was asked just after the December prorogation crisis, when the minority Conservative government almost fell in the face of a challenge from a Liberal-NDP coalition headed by former Liberal leader Stéphane Dion.

It suggested the Conservatives had 44 per cent approval among the Canadian public, with dips for the Liberals (at 24 per cent) and NDP (at 14.5 per cent) compared to vote share those two parties had earned in the Oct. 14 federal election (26.2 per cent and 18.2 per cent respectively).

'Iffy proposition' to retain minority: pollster

EKOS pollster Frank Graves said the latest numbers, accompanied by regional breakdowns showing the Conservatives' level of support well below that of the Liberals in the key battleground provinces of Ontario and Quebec, suggest that "even the question of repeating a minority is an iffy proposition" for Harper's party.

The Liberals and NDP would almost certainly gain seats at the Conservatives' expense if an election were held this spring or summer, Graves pointed out. "There would be little in Stephen Harper's toolkit to discipline an opposition in these circumstances."

The province of Quebec in particular "almost looks like a wasteland for them," the pollster said.

Though the poll's Quebec margin of error is relatively high at plus or minus 5.7 per cent, 19 times out of 20, the Conservatives register only 10.9 per cent support in the province, compared to 39.5 per cent for the Bloc Québécois, 33.0 per cent for the Liberals, 11.7 per cent for the NDP and 4.9 per cent for the Greens.

In the Ontario breakdown, with a margin of error of plus or minus 4.3 per cent, 19 times out of 20, the Conservatives enjoy 32.4 per cent, compared to 42.0 per cent for the Liberals. The two parties were statistically tied the last time EKOS conducted party preference polling.

Conservatives more confident

On the bright side for the Harper team, confidence in both the current government and the Canadian economy are very high among Conservative backers.

Harper has an approval rating of 91 per cent among decided Conservative voters, although he only has a rating of 14 per cent among Liberal voters, 18 per cent among NDP voters, 28 per cent among Greens and 10 per cent among Bloc voters.

"There's a vivid gap between the Conservative base, who are very happy with the general direction of the country, and everyone else," Graves said.

Graves added that the reverse doesn't apply for Ignatieff.

The man who has been Liberal leader for almost four months has approval ratings of 33 per cent among Conservative supporters, as well as a rating of 80 per cent among self-identified Liberals. Ignatieff also fares high among other party supporters — he has a rating of 34 among NDP voters, 44 among Greens and 47 among Bloc voters.