OTTAWA – The opposition Liberal Party has regained its slender lead in public support, thanks largely to a sharp dip in backing for the ruling Conservatives, according to a poll released Thursday.

A weekly Ekos survey for the Canadian Broadcasting Corp put the Liberals at 32.2 per cent, down from 32.6 per cent last week. The Conservatives dropped to 31.0 per cent from 34.8 per cent while the left-leaning New Democratic Party was at 16.2 per cent, up from 14.3 per cent.

Ekos said the Conservatives had lost the short-term advantage they gained the previous week after the Liberals effectively backed down from a threat to bring down the government over the way it was tackling the economic crisis.

"The most striking pattern may be one of gridlock, in which neither major party can break through to become an obvious election favourite, much less a contender for a majority government," the firm said in a statement.

Recent Ekos polls have largely shown the Liberals slightly ahead, but not by enough to guarantee any kind of election victory. Under Canada's first-past-the-post system, a party needs around 36 per cent or 37 per cent of the vote to stand a chance of forming a minority government.

Ekos president Frank Graves said it was possible the poll showed "a passive uninterested electorate, and that the better predictor of an election result is actually those weeks when the public becomes more interested and engaged".

The Conservatives won elections in January 2006 and October 2008, but failed both times to win a majority of the 308 seats in the House of Commons. This means they need the support of other parties to govern.

The Ekos automated telephone survey of 2,262 adults was conducted between June 25 and June 29 and is considered accurate to within 2.1 percentage points, 19 times out of 20.