Thursday is the last day for Canada's federal party leaders to pitch their campaigns to voters before the royal wedding takes over the airwaves.

On Friday, millions around the globe will watch as Prince William marries fiancée Kate Middleton in London. 

Conservative Leader Stephen Harper was taking his campaign in Ontario and Quebec Thursday.  Harper told supporters at a campaign event in Niagara Falls, Ont., that the choice is still between a Conservative majority government and a minority-led Parliament, which he said would raise taxes and spending.

Both Harper and Liberal Leader Michael Ignatieff criticized the NDP, which has seen an apparent increase in support in the final stretch of the campaign.

Ignatieff criticized the NDP platform at an event in Quebec, saying the party's policies should come under increased scrutiny ahead of the May 2 election.

NDP Leader Jack Layton, meanwhile, was in Yellowknife for a campaign event. Layton called on young people to get out and vote on Monday to ensure their voices are heard.

In B.C., Green Party Leader Elizabeth May  was to spend the morning campaigning with Green Party deputy leader Georges Laraque, followed by campaign stops in Saanich and Galiano Island.

Bloc Québécois Leader Gilles Duceppe spent the morning shoring up support in Rivière-du-Loup, followed by stops in Montmagny and Beauport-Limoilou.

He was asked that he thought of both Ignatieff and Harper being in Quebec near the end of the campaign.

"Well, it means certainly there's a fight in Quebec City …," Duceppe said. "I mean, three of us are there. It means there's certainly something happening there, and it is a very, how could I say that, it's a hard fight for each of us."

On Wednesday, former prime minister Jean Chrétien  attempted to rally Liberal support, blasting the Conservatives and NDP.

Chrétien told the crowd gathered in Toronto he feared for the country Canada was becoming, saying Canadians could start to lose their values "one by one" if they're not careful.

Chrétien revived the notion of a hidden Conservative agenda, warning supporters that a Harper majority would find underhanded ways to undermine minority rights.

He also accused the Tories of taking credit for Liberal economic policies that he says helped get Canada through the recession.

After days spent barely acknowledging the NDP's momentum, Harper continued his attack against the NDP Wednesday, urging Canadians to vote Conservative.

Harper said the NDP can't be trusted with the economy, and accused the party of planning for huge spending increases and higher taxes.

'Not all smiles and snake oil': Harper

"It matters very much who is making the big decisions. The big decisions, sometimes the tough decisions, they're not all easy decisions. They're not all smiles and snake oil," Harper said.

"Get the big decisions wrong and it will take a generation to dig ourselves out. Those here who remember the Liberal-NDP arrangement of the 1970s remember how it took a generation to dig ourselves back out.  I don't have to remind what it took here after an NDP government in the province of Ontario."

Harper was referring to Pierre Trudeau's minority government in 1972 that was supported by David Lewis's NDP, and to the Ontario NDP government of Bob Rae in the early 1990s.

Layton, however, appeared unruffled by the barbs.

He acknowledged the attacks by the "old parties," and repeated a pledge to bring attacks of his own — to emergency room wait times, doctor shortages, seniors' poverty and retirement security.

Layton seeks Alberta gains

Layton returned to Alberta on Wednesday night trying to expand his party's foothold in the Conservative stronghold.

Harper's Conservatives held 27 of Alberta's 28 seats when the election was called. The sole holdout was Edmonton-Strathcona, which was held by the NDP's Linda Duncan.

Layton ventured into Edmonton early in the campaign, when the polls still had him languishing far behind the Liberals and Conservatives. Now the NDP has momentum, and the party is making a play for ridings in areas that would have been considered long shots in the past.

"It's great to be here, where they used to say change could never happen," Layton said.

Layton's call to Alberta's New Democrats is getting bolder, The NDP leader focused his criticism on Harper and asked supporters to help elect a NDP government.

"You deserve a prime minister you can trust, a prime minister who will work with others, a prime minister who can get things done, and I'm running to be that prime minister," Layton said.

More than 700 New Democrats crowded together to hear Layton speak on Wednesday, a number nearly unimaginable in Edmonton in previous elections.

The party supporters were buoyed by the boost in public support the NDP says it's attracting.

Martin Tweedale is one of the many Alberta New Democrats who have been waiting years to see the party's fortunes rise in his province. Tweedale has been a New Democrat for 10 years, and at times, he admits, it's been lonely.

"Well, you know, you get used to just operating with a minority, and a fairly small minority, and you make as much noise as you can, and laugh off the rest of it," he said.

With files from The Canadian Press