OTTAWA (Reuters) - Canada's ruling Conservatives, buoyed by polls showing they are starting to break away in the run-up to the Oct. 19 election, predict they will do even better than forecast given their past ability to beat polls that underestimate voter support.
Prime Minister Stephen Harper's Conservatives, seeking a rare fourth consecutive term, had 34 percent support in an Angus Reid poll released on Thursday, compared with 27 percent support for the rival Liberals and New Democrats.
For weeks polls had shown a three-way tie between the major parties, raising the specter of political instability after the election and market instability that could affect the Canadian dollar, already sitting around 11-year lows.
Party insiders note the Conservatives have historically captured about 3 percentage points more than polling numbers heading into the ballot box.
Eric Grenier, of the poll-aggregating website ThreeHundredEight.com, said that pattern, set in 2008 and 2011, may not be repeated this time around, with voters suffering from some fatigue after nearly 10 years of Harper.
"If you had to bet will he go over or under (the polling number), I think over is probably the safer bet. Whether it will be two or three points is something that's impossible to say," he said.
If the Conservatives do win 37 percent of the vote, they would have a theoretical chance at winning a majority, an outcome that seemed unlikely for much of the 11-week campaign. Failing that, the party would win a reasonably strong minority that would make it more difficult for the opposition parties to justify bringing them down.
Two Conservative sources said the party planned to launch "a wave of very hard-hitting ads" in the run-up to Canada's Oct. 12 Thanksgiving holiday, focusing on Liberal leader Justin Trudeau. The Conservatives have consistently attacked the youthful Trudeau, age 43, as not ready to lead Canada.
Conservative campaign spokesman Kory Teneycke declined to comment when asked about polling patterns or the content of the series of commercials the campaign shot on Wednesday.
"There will be ads on a variety of topics, some positive, some which provide contrast," he said on Thursday.
An expansion of seats in the House of Commons to 338 from 308 may also boost the Conservatives, with many of the new seats in areas where Conservative support is already healthy. Party sources say they are confident the party will win at least 20 of the new 30 seats.
Reporting by David Ljunggren and Randall Palmer; Editing by Leslie Adler