OTTAWA (Reuters) - Canada's governing Conservatives are still ahead of their main rivals in public support, but would have little chance of forming a stable government if an election were held now, according to a poll released on Thursday.
The weekly Ekos survey for the Canadian Broadcasting Corp put the Conservatives at 33.6 percent, up from 32.2 percent last week. Support for the main opposition Liberals rose to 27.3 percent from 27.0 percent.
Under Canada's first-past-the-post-electoral system -- where the candidate with the most votes in each constituency wins -- a party needs at least 40 percent public support to capture a majority of the 308 seats in the House of Commons.
To win a workable minority government, it needs around 36 percent.
The Conservatives won a minority in an October 2008 election, and need the support of at least one opposition party to govern.
The survey also showed a solid majority against the idea of extending the country's 2,900-strong military mission to Afghanistan, which is due to end next year.
Ottawa says it will only extend the Afghan mission if Parliament approves the idea.
The Ekos automated telephone survey of 797 adult voters was conducted between March 31 and April 6 and is considered accurate to within 3.5 percentage points, 19 times out of 20.
Reporting by David Ljunggren; editing by Janet Guttsman