OTTAWA, Ontario – After a month of campaigning, the three-way race for Canada's Oct. 19 election has narrowed as warning signs emerge for Prime Minister Stephen Harper in his bid for a fourth consecutive term.

The Conservative has endured an explosive court case, talk of a recession and a migrant crisis that have eroded his traditional core platform planks: accountability and economic stewardship. Tom Mulcair of the leftist New Democratic Party and Justin Trudeau of the centrist Liberals, meanwhile, are each working to position themselves as the best alternative to Harper.

Polls have shown the three parties essentially tied — though one, published Monday night by Nanos Research, suggests Harper has sunk to third place. The deadlock may break as Canada emerges from an end-of-summer long weekend, with students returning to classrooms and workers settling back into routine.

"The campaign to date has been largely a phone campaign producing little attention," said Frank Graves of Ekos Research. "All of this will change post-Labour Day as the real war for votes begins in earnest."

An Ekos poll published Friday showed Mulcair's New Democrats in the lead with 30.2 percent support, Harper's Conservatives at 29.5 percent and Trudeau's Liberals close behind at 27.7 percent. Monday's Nanos survey, conducted for CTV and the Globe and Mail, found the NDP ahead with 32.7 percent, followed by the Liberals at 30.8 percent and Harper at 26.2 percent.

The election's first month included two weeks of testimony in the criminal trial of former Conservative Sen. Mike Duffy that exposed the inner workings of Harper's office and a plan to cover up disputed expenses. While explosive, that testimony has largely been forgotten, Graves said.

It's been overshadowed by Canada's economy — typically a Conservative strength.

Figures released Sept. 1 showed plunging oil prices sent the country into a technical recession, with gross domestic product contracting for two consecutive quarters to start the year. The Bank of Canada has cut interest rates twice this year and investors see only slim odds of a third move when policymakers meet again Wednesday. However an uptick in GDP in June and a resilient labor market allow Harper to say the economy is "back on track."

The prime minister also faced the campaign's first true curveball last week after an image of a dead Syrian boy washed up on a Turkish beach captured the world's attention. On Sept. 3, it was revealed the boy's uncle had sought refugee status in Canada and was refused, and that a Canadian relative had appealed directly to Harper's immigration minister for help, to no avail.

While expressing sympathy for the hundreds of thousands driven from their homes in Syria and Iraq, Harper emphasized the need for Canada to continue its involvement in the military campaign against Islamic State in Iraq and the Levant — a key differentiation point with his opponents.

Campaigns will now shift into high gear. The NDP and Liberals will ramp up their leaders' tours and advertising efforts, and all three parties will finish their platforms. There are also four debates scheduled, the first of them focused on the economy set for Sept. 17 in Calgary, Alberta.