OTTAWA - Stephen Harper is making his most direct pitch yet for a majority mandate from Canadian voters, saying it will require a forceful government in Ottawa to weather the financial turbulence on the horizon.

"In a time of economic uncertainty, I do think the country needs a strong government that's able to govern," the prime minister told a group of reporters from ethnic newspaper and broadcast outlets Tuesday.

"My concern is that, obviously, going forward, that we have a government that's going to be sabotaged by a bunch of parties who don't want our economy to be successful."

Harper didn't stop there, telling the same media session in Mississauga, Ont., that he also needs a "strong mandate" to fight crime and preserve law and order.

"'The other parties do not believe in tougher laws against criminals," Harper declared. "They will fight those laws, they will amend those laws, they will obstruct those laws."

It was a sharp change of tone for the Conservative leader, who began the campaign a little more than a week ago resolutely refusing to speculate on his chances of winning a majority.

Poll results in the early going showed him flirting with majority territory and making inroads with urban and female voters, two target groups crucial to his electoral chances. But since then the Tory numbers have slipped, as some voters leery of the party's message apparently fled to the Liberals or NDP.

Despite the recent dip, the Conservatives continue to hold a healthy lead in most polls. But Harper took pains to warn his supporters not to take too much comfort from that.

"Don't take anything for granted," he told an evening rally aimed at steeling the resolve of his troops. "We need every vote we can get, we need every seat we can get."

Harper's shift in approach coincides with the emergence of the economy as an overriding issue in the campaign -- in large part because of the market meltdown in the United States that followed the collapse of Wall Street titans Lehman Brothers and Merrill Lynch.

Those events, in turn, have heightened fears that the troubles could spook consumers in Canada and lead to a wider economic slump in both countries.

As Harper responded to the concerns, Liberal Leader Stephane Dion was moving to shore up perceived weaknesses in his leadership, enlisting high-profile Grits to help sell his controversial Green Shift and to sharpen his attacks on the Conservatives.

Former leadership rival Bob Rae joined the Dion campaign in Halifax to lend support and dispel media stories quoting "anonymous sources" grumbling about the leader.

Party spokesman Mark Dunn said other Liberal luminaries, including one-time leadership rival Michael Ignatieff and former minister Belinda Stronach, who is not running this time, will also be joining the Dion tour.

But he denied the campaign was low-bridging the leader by emphasizing the Liberal team, saying Dion would continue to be the "front man of the band" and that Rae was an "accompanying player."

Rae played the tune to the hilt when he got his chance.

"I'm not an anonymous Liberal. I'm Bob Rae. I'm tremendously proud of our leader, Stephane Dion," and the campaign he has waged, Rae told reporters.

In contrast, he added: "From Mr. Harper . . . we have ideology, we have personal attacks, we have negativity and we have Herbert Hoover in a blue sweater."

The visible show of support from a former rival comes at a time when Harper and the NDP's Jack Layton have both denounced Dion's plan to impose new carbon levies while at the same time cutting income taxes in an effort to increase incentives for green technologies.

It seemed to energize Dion, who delivered possibly his best line of the campaign while addressing a well-publicized weaknesses.

"Mr. Harper, he speaks better English than me, OK. But I speak the truth better than him in English and in French," he said.

Harper, as he has for days, sounded the alarm Tuesday about the Liberal Green Shift plan, calling it risky, radical and even "crazy."

The economy has problems, Harper told a rally in Kitchener, Ont., but the country is not in recession.

This is no time to preach "doom and gloom," or to experiment with the economy, he said, while introducing a new tax credit that he said could save first-time home buyers up to $750 on closing costs.

Harper was confronted by an organized protest from the Canadian Auto Workers, but did not veer from his message that his party's no-surprises approach was best.

"Our opponents do have a wild, grand plan, they want to massively increase spending and one of them (Dion) wants to raise taxes to cover it all. That's a radical departure, I also think it's an unwise one," the prime minister charged.

Layton, who like Harper found himself in southwestern Ontario, has said the Green Shift won't work. However, he has proposed spending $8.2 billion to stimulate the manufacturing sector, including creating "green-collar" jobs for such things as hybrid cars.

He upped the ante Tuesday at a rally in front of a John Deere plant, the site of recent layoffs, promising to spend $100 million on job creation and training.

Layton assailed the government for cutting corporate taxes without insisting that jobs be protected at the same time.

"No politician can guarantee jobs, but what you can guarantee is that you are going to fight for those jobs," he said.

Dion also had a new campaign promise, saying he would spend $900 million on a plan to protect patients against catastrophic drug costs.

But it was defending the Green Shift from accusations that it is a massive tax grab that again proved the most problematic task for the Liberal leader.

He urged Canadians to go to the party website to see how they would personally fare -- then began listing a few examples which suggested families with incomes under $50,000 would be net winners.

The Green Shift is a comprehensive approach to build the economy of the future, he said, while the Conservatives offer only more of the same old policies.

"He's saying, `Don't worry, be happy.' In his words, `There is no bloodshed,"' Dion said of Harper.

"Well, tell that to the hundreds of people who lost their jobs at Ford last week. The hundreds who lost their jobs at John Deere."

Green Leader Elizabeth May made noises Tuesday as she attacked Peter MacKay, Harper's defence minister and her Conservative rival in the Nova Scotia riding of Central Nova, for dropping a major military contract with a local knife supplier.

Grohmann Knives have been used for decades by Canadian soldiers, but the contract has suddenly gone to a company in China, May said.