OTTAWA (Reuters) - Public support for the ruling Conservatives is dropping amid controversy over how much a pair of big international summits will cost, and the party might not win a viable minority government if an election were held now, according to a poll released on Monday.
The Nanos Research survey put backing for the Conservatives at 35.6 percent, down from 37.2 percent in a poll done by the same firm a month ago. The main opposition Liberal Party was at 29.2 percent, down from 33.2 percent.
Under Canada's electoral system, a party needs at least 40 percent public support to capture a majority of the 308 seats in the House of Commons, and around 36 percent to win a workable minority.
Pollster Nik Nanos said the dip in Conservative support followed increasingly sharp questions about why the government planned to spend C$1 billion ($945 million) on security for the summits of the Group of Eight and Group of 20 nations.
The G8 summit will take place in Huntsville, Ontario, from June 25 to 26 and the G20 will be held in Toronto June 26 and 27. The government says the security costs are reasonable.
Nanos noted that Conservative backing was down in the party's Western Canadian heartland.
"I think a lot of that is likely negative blowback from the billion dollar G8/G20 summits. The Conservative core can't be happy when they see something like this happening," he told told Reuters in an interview.
"For average Canadians, this seems like a fundamental disconnect," he said.
Government ministers were grilled -- and on occasion openly laughed at -- by opposition members in the House of Commons on Monday after it emerged that Ottawa would spend C$1.9 million on a fake lake at the summit media center in Toronto.
The Conservatives won a strengthened minority in the October 2008 election and have until recently insisted the public does not want to return to the polls again soon.
However, the Nanos survey had little good news for the main opposition Liberal Party, which lost power in the January 2006 election and has struggled in recent months under leader Michael Ignatieff.
The Liberals are locked in a battle for support with the left-leaning New Democrats, whose backing jumped to 20.7 percent from 16.2 percent a month ago. The higher the backing for the New Democrats -- who have never held power nationally -- the harder it is for the Liberals to win an election.
The Nanos poll of 1,008 people was conducted between May 29 and June 3 and is considered accurate to within 3.1 percentage points, 19 times out of 20.
Reporting by David Ljunggren; editing by Rob Wilson