The Conservatives released a fresh attack ad aimed squarely at NDP Leader Jack Layton on Friday, reflecting a new reality in Canada's federal election campaign — the New Democrats are rising in the polls at the expense of the other parties.

The advertisement, posted on YouTube, slams Layton as "blindly ambitious" and willing to conspire with the Bloc to form a government.

In the 2008 election, it says, "Layton began planning a coalition with the Bloc Québécois before our votes were even counted." It finishes: "He did it before. He'll do it again. And Canada will pay the price."

New Democrat Paul Dewar, who is running in Ottawa-Centre, called on the Tories to pull the ad and accused them of hypocrisy, noting they demanded the Liberals pull ads they claimed were false.

"The entire ad is based on complete fabrications," he said. "The ad makes three accusations; each one them is made up."

Layton, who took part in a Good Friday event in Toronto, told reporters he hadn't seen the ad.

It came on an otherwise quiet campaign day allowing for religious observances of Good Friday and Passover. The week ended with polls showing a surprising surge for the NDP in Quebec and across Canada.

An online survey done by CROP, which cannot be assigned a margin of error because the methodology doesn't allow for random sampling, suggested the NDP had the support of 36 per cent of respondents in Quebec, compared with 31 per cent for the Bloc Québécois.

A poll from Nanos, meanwhile, showed the NDP gaining in support nationally, but the sample size for Quebec was too small to give results within an acceptable margin of error.

An Ekos poll for iPolitics.ca released Thursday suggested the NDP and Liberals were tied at 24.7 per cent voter support nationally, behind the Conservatives at 34 per cent. Support for the Greens was at 7.8 per cent, while the Bloc trailed at 6.5 per cent, according to the survey.

Friday brought a day off for two federal party leaders, as the holiday weekend began and advance polls opened ahead of the May 2 vote. 

Neither Conservative Leader Stephen Harper nor Ignatieff had events scheduled on Friday — a day of religious observance for the Christians at the start of the Easter weekend, and for the Jewish community marking the final days of Passover.    

Meanwhile Bloc Québécois Leader Gilles Duceppe had three different campaign stops scheduled in Quebec.

 Duceppe said he believed most Quebecers want to avoid giving the Conservatives a majority. The way to do that, he said, is to turn out to vote in higher numbers than in 2008 and to support the Bloc.

"We’ll fight very hard to the very end to stop them from getting a majority," he said during a campaign stop in Val d'Or.

Later in the day, the Bloc leader tweeted that voters shouldn't be fooled by the NDP "mirage" in Quebec.

For their part, the Liberals issued a video invitation to their 30-minute televised "town hall for Canada " on Sunday. In it, Ignatieff tries to take the personalities out of the equation.

"This isn't about Stephen Harper," Ignatieff says in the video. "It isn't about Michael Ignatieff. It's about Canada. It's about what kind of Canada you want."

Holiday polls defended

Meanwhile, Archbishop of Ottawa Terrence Prendergast said Elections Canada must examine how advance poll dates are set in future votes to prevent them from being held on such significant religious holidays as Easter.

P.O.V.:

Are you voting at an advance poll? Tell us about your voting experience.

"The decision's made by the parties when they chose the date for the election. The law tells you how many days in advance you have to have the poll," Prendergast told CBC News on Friday.

"I think if they had seen this and foreseen this, they would have asked the Parliament to change the dates, but of course Parliament had already been dissolved, so that's difficult. I think they should think about this for the future."

But John Enright, spokesman for Elections Canada, defended the polls, saying the dates are prescribed by the Elections Act, which does not allow any flexibility in determining them.

He said the elections body appreciates that the dates fall both on a Christian and Jewish holiday, but added voters have other options, such as voting by mail or in person at a local returns office during business hours.

"And let's not forget May 2, a regular voting day where polls will be open for 12 hours," Enright told CBC News.

Right of 2nd party to govern 'question of debate': Harper

With the prospect of another minority government looming, talk turned again to possible coalitions and how a government might be formed if no one party wins a clear majority of seats in the House of Commons.

In an exclusive interview with CBC chief correspondent Peter Mansbridge Thursday, Harper said he wouldn't try to govern if his party doesn't win the most seats.

Nor did he agree that the other parties have the right to attempt to form a government even if together they have enough seats and the Governor General asks one to attempt it.

"I do think most Canadians would still be very surprised if they elected a Conservative minority and found out they had some completely different kind of government. I think that would be a big shock to people," Harper said.

"My view is that the people of Canada expect the party that wins the election to govern the country. I think anything else the public would not buy."

When Mansbridge said the other parties had a right to try to form a government, Harper replied: "That's a question of debate, of constitutional law."

In a similar one-on-one interview with Mansbridge Tuesday,  Ignatieff said he would be willing to form a government according to parliamentary rules if Harper wins the most seats in the election but fails to win the confidence of the House of Commons.

"If the Governor General wants to call on other parties, or myself, for example, to try and form a government, then we try to form a government," Ignatieff said.

The NDP is attempting to seize on this swing in popularity by sending Layton into Duceppe's riding for a rally on Saturday.

When the election was called, the Bloc held 47 of Quebec's 75 seats, but the sudden shift in apparent voter intention toward the NDP is forcing Duceppe to change his tactics, taking full aim at Layton and trotting out some star power from the Quebec sovereignty movement.