Prime Minister Stephen Harper, left, Liberal Leader Michael Ignatieff, centre, and NDP Leader Jack Layton take in events at the Calgary Stampede in July. (Jeff McIntosh/Canadian Press)

The Liberals are tied for support with the Conservatives as the possibility of a fall federal election looms, a new EKOS poll released exclusively to CBC News suggests.

Asked which party they would vote for were a federal election held tomorrow, 32.6 per cent of respondents said they would cast their ballots for Stephen Harper's Tories, while the same percentage opted for Michael Ignatieff's Liberals, EKOS said.

The Liberal numbers represent a slight boost from the previous week, as well as a significant boost in the party's support from a year ago, when the Conservatives enjoyed a 13-percentage-point lead over the Liberals under Stéphane Dion's leadership ahead of the last federal election.

The Liberals have erased a small but persistent lead enjoyed by the Tories throughout most of the summer by improving their fortunes in the battleground province of Ontario, EKOS said.

The latest survey was conducted between Aug. 26 and Tuesday, the day Ignatieff announced his party would no longer support Harper's minority government in the coming fall session in the House of Commons. The move increases the prospects of a government defeat and a fall election. The poll did not survey respondents on the weekend.

"So as media interest begins to percolate, and the public inevitably and perhaps reluctantly return their attention again to politics, it appears that the race would now be handicapped as 'pick 'em' between the two main contenders,” EKOS president Frank Graves said.

About 16.5 per cent of respondents supported the NDP, while the Green party was the choice of 9.9 per cent and the Bloc Québécois was backed by 8.3 per cent.

The deadlock in support indicates the prospect of one of the sides forming a majority government is a long shot, Graves said.

The poll surveyed 2,118 Canadians aged 18 and over — of whom 1,772 were decided voters — using interactive voice recognition technology, which according to EKOS "allows respondents to enter their preferences by punching the keypad on their phone, rather than telling them to an operator."

It has a margin of error of plus or minus 2.1 percentage points, 19 times out of 20.