Conservative Party Leader Stephen Harper talks with the Huang family — father Edwin Huang, 14-month-old Eric, four-year-old Renee and mother Fei Chen — on Monday at their Richmond, B.C., home. ((Tom Hanson/Canadian Press))

Stephen Harper labelled Stéphane Dion's policies as "untested schemes" during his campaigning Monday, while the Liberal leader challenged the prime minister to an "honest debate" on his carbon tax plan.

Speaking at a private home in Richmond, B.C., Harper said his Conservatives have the "sensible balance" to handle uncertain economic times, while portraying his Liberal opponents as reckless tax-and-spenders.

"Our opponents have a not-so-hidden agenda," said Harper, who accused the Liberals of favouring a higher GST and promising to scrap the Conservatives' popular $1,200-per-year child-care benefit.

But he saved the bulk of his criticism for Dion's Green Shift carbon tax plan, saying the Liberals were "asking Canadians to sign up for a permanent new category of taxation."

PM's allegations 'open lies': Dion


Liberal Leader Stéphane Dion shakes hands with a supporter in Saint-Lambert, Que., on Monday. ((Adrian Wyld/Canadian Press))

Speaking earlier, Dion decried the Tories' latest allegations over the GST and the child-care benefit as "open lies" and in turn targeted Harper's "laissez-faire" approach to Canada's economic woes.

Dion added his so-called Green Shift carbon tax plan would benefit a majority of Canadians and is a direction recommended by a "great number" of economists and environmentalists.

"I call on Mr. Harper … to not try to win an election by lying, and to be honest for once," Dion said at a campaign appearance in Saint-Lambert, Que. "He's afraid to debate honestly, but for once he will have to do so."

Dion also told reporters he would not raise the GST, which the Conservatives cut by two percentage points to five per cent since they took power in 2006.

But the Tory leader said Dion voted twice against cutting the GST and then said afterwards he would raise it again.

"And, if he's saying he wouldn't now, that's not credible," Harper said.

The Liberal leader said Harper's Conservatives have watched idly as Canada's economic growth outlook dwindled to the worst of the G8 industrialized nations.

"He's creating a mess for this economy," Dion said. "We'll clear the mess they have made and we'll put this economy on track."

Last week, the Paris-based Organization for Economic Co-operation and Development downgraded Canada's expected growth for the year to 0.8 per cent — near the bottom of G7 countries, just above Italy.

The OECD figure is a far cry from the economy the Tories inherited in 2006, which was growing at an annual rate of 3.1 per cent.

Harper has insisted Canada's economic fundamentals are strong and said his party is the strongest to handle future economic uncertainty, while saying all Dion offered was his "risky" carbon tax plan.

Layton targets oilsands pollution

Meanwhile on Monday, NDP Leader Jack Layton travelled to the Northwest Territories community of Fort Smith, but not to address any key ridings, said the CBC's Rosemary Barton, who is with the campaign.

Layton went to Fort Smith to draw attention to how he said the prime minister is letting oilsands development spin out of control, Barton said.

Earlier in the day, as the plane flew over the oilsands of northern Alberta, it dipped down to 5,000 feet so everyone could get a better look. Layton watched intently out the window at the huge swaths of inky water with roads running in and out, Barton reported.

"Who is going to clean this all up?" he later asked.

Layton, who was heading to Vancouver for an afternoon event at the Italian Cultural Centre, has said he will put a moratorium on further oilsands development in Alberta.

Duceppe welcomes federalist votes

Also on Monday, Bloc Québécois Leader Gilles Duceppe said federalists can vote safely for his party without supporting Quebec sovereignty.

Duceppe, who began his campaign in Trois-Rivières before heading to Quebec City, told reporters that sovereignty will be decided in Quebec, not in Ottawa.

He noted that federalist parties have a documented history of asking sovereigntists to vote for them in elections, support that doesn't prevent someone from endorsing separation in a referendum.

"Mr. [Jean-Pierre] Blackburn does it very openly. He tells Péquistes, even if you are sovereigntist, 'That's OK, you can vote for me.' Well, if that reasoning holds for them, it also holds for us," Duceppe told reporters after he inaugurated Bloc MP Paule Brunelle's election office in Trois-Rivières.

Dion's own appearances in Quebec at the beginning of the campaign is aimed at building support in key ridings in a province where his party appears to be struggling.

A poll released Monday suggests the Liberals trailing the Conservatives and the Bloc in Quebec by a significant margin.

The Segma poll, published in La Presse, reports the Liberals at 17 per cent of the total vote, down from 21 per cent in the 2006 election, with the Bloc Québécois at 35 per cent of the vote, edging out the Conservatives, at 30 per cent.

With files from the Canadian Press