Prime Minister Stephen Harper may go to the Governor General as early as Sept. 5 to ask for a general election, senior Conservative sources have told CTV News.

That would cancel four byelections already scheduled for next month, with three set for Sept. 8. Campaigns have already kicked into gear in the Guelph riding of Southwestern Ontario, and the Quebec ridings of Westmount-Ville Marie in Montreal and nearby Saint Lambert.

A fourth byelection in the Toronto riding of Don Valley West is scheduled for Sept. 22.

Liberal candidate Marc Garneau, who is running in Westmount-Ville Marie, said the Conservatives want an election to avoid addressing issues like the economy.

"I'm not surprised the Harper government is doing this because I think they're very embarrassed the economy is softening, and they have nothing to propose to Canadians," he told CTV News.

Sources say Conservatives favour a short election campaign because anything longer would waste taxpayers' money. The shortest allowed by law is 37 days, so an election call on Sept. 5 would mean a vote on Thanksgiving Monday. Because of the holiday, the vote would be pushed to Tuesday Oct. 14.

That would send Canadians to the ballot box before the U.S. holds its presidential election on Nov. 4. Some analysts believe a Democratic win by Barack Obama would help the Liberals north of the border.

"There's something coordinated about all of this," said NDP Leader Jack Layton. "I think it's a charade. Harper's up to no good here."

Harper has said Parliament has become too "dysfunctional" to continue, although his governmental has legislated a fixed election date for October 2009.

Liberal Leader Stephane Dion has been coy about triggering an election, saying he wants to wait until Canadians are ready to head to the polls.

For the past 10 days, senior government officials have been signalling they don't believe Dion is serious about allowing Parliament to work. But in Saskatoon on Sunday, Dion said he's ready to meet the prime minister.

"Parliament is working. Parliament is not dysfunctional. This is an invention by Mr. Harper to trigger an election," he said.

With a report by CTV's Graham Richardson in Ottawa