Prime Minister Stephen Harper speaks with media following a caucus meeting in Ottawa last week. An EKOS poll suggests Harper's Tories would be slightly ahead of the Liberals if an election were held tomorrow. (Adrian Wyld/Canadian Press)The federal Conservatives have pulled slightly ahead of the Liberals in voter support for the first time in months, according to a new EKOS poll released exclusively to CBC News after a week of political brinkmanship that saw Michael Ignatieff threaten to trigger a summer election.

Asked which party they would support if a federal election were held tomorrow, 34.8 per cent of respondents said they would cast their ballots for Stephen Harper's Tories, while 32.6 per cent opted for Ignatieff's Liberals, EKOS said.

The Liberal numbers in the poll released Thursday are a drop from the 33.5 per cent support reported in a similar EKOS poll conducted last week.

About 14.3 per cent supported the NDP, while the Green party was the choice of 9.3 per cent and the Bloc Québécois was backed by nine per cent.

The latest survey was conducted between June 17 and June 23, and involved a random sample of 3,505 Canadians, using Interactive Voice Recognition (IVR) 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 1.7 percentage points, 19 times out of 20.

'Not a good week' for Liberals: pollster

Liberal Leader Michael Ignatieff is seen leaving a meeting with Prime Minister Stephen Harper last week. The two reached a deal to form a study panel to examine employment insurance. (Sean Kilpatrick/Canadian Press)

The polling window ended six days after Ignatieff and Harper announced they had reached a deal to form a study panel to examine employment insurance over the summer in exchange for the Liberals' support of the minority Conservative government in a House vote.

Ignatieff had previously threatened to withhold confidence in the vote unless the prime minister gave him answers surrounding EI reforms, as well as the rate of stimulus spending, the government's plan to contain the ballooning deficit and its plan to deal with Canada's medical isotopes shortage.

EKOS president Frank Graves said the poll shows it was "not a good week at all" for the Liberals, but added the slip in support could be a "short-term political setback.

"This may be a very temporary jump," Graves said.

But he cited the key "boomers" group, aged 45 to 65 and known for being politically engaged, as an area of concern for Ignatieff's party. He said more boomers appear to be returning to the Conservative fold as financial markets begin to recover from the global economic downturn.

"The boomers are looking at their 'Freedom 55' which became 'Freedom 95," he said. "But now things are looking a little better."

In the battleground province of Ontario, the Tories and Liberals are neck and neck with 38.2 per cent support after previous polls in recent weeks suggested the Liberals were widening their lead in the province.

According to the latest EKOS poll, Ignatieff's job approval rating also took a hit, with 37 per cent of respondents disapproving of his performance, compared to 32 per cent of respondents who approved.

Meanwhile, Harper's numbers improved slightly from last week, with 34 per cent of respondents approving and 46 per cent disapproving.

Graves said the numbers could indicate the Tories' negative advertising, coupled with less than glowing media coverage of last week's standoff, could be corroding Ignatieff's support after months of positive approval ratings.

"The advantage he had is clearly much smaller," he said.