NDP Leader Jack Layton took aim at the Conservative government's job-creation record during a campaign swing through southern Ontario on Tuesday.

Layton took his message of creating new jobs to a town hall meeting in Welland, Ont., on Tuesday afternoon.

The NDP leader continued to chastise Conservative Leader Stephen Harper over a series of local businesses that closed in the area.

Layton kept to his campaign theme of slamming the Conservatives' tax cuts for large corporations. He also promised the crowd that he would do what he could to keep businesses from shutting down.

"And as your prime minister, I will fight like hell for your jobs," Layton said.

Layton and Liberal Leader Michael Ignatieff returned to southern Ontario on Tuesday as the leaders targeted ridings in the vote-rich area.

Layton spoke to reporters on Tuesday morning in Toronto before travelling to Welland, Ont., where he is trying to hang onto ridings he currently holds in the region.

The Conservatives have made a strong pitch for ridings, especially Welland, where Stephen Harper renewed calls to scrap the gun registry, using it as a wedge issue in the hope of taking the riding from the NDP.

Layton directly challenged Harper on his decision to campaign in Welland without mentioning the issue of jobs.

"And then Stephen Harper had the gall to come to here in this campaign and not mention jobs once," Layton said.

"When the prime minister comes to Welland and doesn't talk about jobs, we know Ottawa is broken."

The NDP leader listed several local businesses, such as John Deere, a CanGrow canner, Henniges Auto and Smuckers, that cut jobs or shipped them elsewhere.

Layton told the friendly audience that perhaps the job closures were evidence of a different style of Conservative job creation plan.

"To be fair, Mr. Harper insists he does have a job creation strategy - you'll just have to go to the U.S. to find it," Layton said.

While his most pointed attacks were aimed at Harper, Layton also continued to challenge Ignatieff on why he has supported the Conservative government on so many votes and why he failed to show up for the majority of votes in the House of Commons.

Conservative Leader Stephen Harper campaigned with area candidates in Thunder Bay, Ont., Tuesday morning before heading to a rally in Val-d'Or, Que., in the evening.

'Weak' Liberal government 'last thing' Canada needs: Harper

Harper questioned why Canada is in an election campaign at all, when the parties that set it in motion by defeating the Conservative government in Parliament "aren't even sure they can win on their own."

"The Liberals, the NDP and the Bloc Québécois believe that this time, in another minority Parliament, they can get together in some fashion and run the country," he said.

"And friends, that's why this time, we have to put an end to this political uncertainty, focus on the economy and jobs by giving Canada a strong, stable, national majority government."

Harper said "the last thing Canada needs in the middle of an economic recovery, is a weak, Liberal government beholden to the Bloc Québécois, raising taxes and going back to the days of consitutional squabbling."

Harper, speaking at the Thunder Bay Regional Research Institute, said his government has invested heavily in health care research to help combat cancer, diabetes, strokes, and neurological ailments.

"Diseases like Lou Gehrig's, multiple sclerosis and Alzheimer's touch too many families," he said. "That's why I am so proud that Canada has long been a leader in brain research."

Liberal volunteer charged

Ignatieff started the day with an appearance in Winnipeg. In the afternoon, the Liberal Leader took part in an exclusive interview with CBC News chief correspondent Peter Mansbridge, part of a series of one-on-one interviews with the party leaders. .

The Liberal leader was heading to Brampton West on Tuesday evening, where a Liberal campaign volunteer has reportedly been charged with stealing a Tory opponent's signs. The volunteer is scheduled to appear in court, but not until May 11, nine days after the election.

Bloc Québécois Leader Gilles Duceppe spent the day in Montreal, meeting with women's groups and community groups, before heading to a meeting in Laval, Que., in the evening.

Green Party Leader Elizabeth May campaigned in Calgary, including a walk on Stephen Avenue and a speech at a local mall. Later in the day she was taking party in a series of events on Saturna Island, B.C.

Canadians to pick Harper quote for Liberal attack ad

On Monday, the Liberals said they would amend an attack ad  on health care that misquotes Harper, but maintained the thrust of the message won't change.

The Liberal ad, which has been airing on TV for a week, accuses Harper of saying the Canada Health Act should be scrapped.

The Conservatives said the comment actually came from David Somerville, the former head of the National Citizens Coalition, and they demanded the Liberals pull the ad and offer an apology.

The Liberals had correctly attributed the remarks to Somerville in 2004.

Ignatieff defended the quote, saying it was taken from "extremely reputable sources," including Maclean's magazine and the Globe and Mail.

The Globe later corrected its story, prompting the Liberals to say they would change the ad.

With files from The Canadian Press