With polls showing the NDP and Liberals battling for second place, Liberal Leader Michael Ignatieff lashed out Tuesday and suggested the New Democrats are "boy scouts" who are not ready to govern.
A Jack Layton government would be a mistake, he said, especially on a file like Afghanistan, where the NDP has demanded Canadian troops be pulled out immediately.
"Come on, folks, let's be serious," Ignatieff said in Vancouver Tuesday.
"We've got to choose a government on the 2nd of May; we can't choose a bunch of boy scouts on this issue."
Ignatieff insisted a vote for the Liberals is the only true alternative to a Conservative majority.
"If you vote for Mr. Layton, you're going to get a Harper minority government. If you vote for Mr. Duceppe, you're going to get a Harper minority government," Ignatieff said.
It's an argument Ignatieff has been making the entire campaign and one that is starting to lose its weight, as some polls show the NDP to be passing the Liberals for second place.
Much of the NDP's newfound strength has been in Quebec, where many of their candidates are young and relatively inexperienced.
Ignatieff pounced on that issue, showing off his Liberal team in a photo-op that included many former cabinet ministers who have handled the big files like the economy and Afghanistan.
The NDP can expect the scrutiny to continue throughout the dying days of the campaign.
The NDP currently has just one MP in Quebec, deputy leader Thomas Mulcair, but according to some projections the party could garner as many as 14 or 15 seats in the May 2 election if poll numbers hold true, said CTV's parliamentary correspondent Richard Madan.
That has Bloc Leader Gilles Duceppe scrambling to maintain his own support, even bringing out separatist icon Jacques Parizeau on Monday to warn people about the risks of voting for the New Democrats.
And on Tuesday a Liberal news release took aim at the NDP over what it referred to as "empty promises on health care."
The release questioned Layton's pledge to hire 1,200 doctors and 6,000 nurses at an estimated cost of $25 million per year, saying the math simply doesn't add up.
Hiring that many medical professionals "amounts to an annual salary of $3,472 per year. Is that enough to hire 7,200 new medical professionals? Not a chance, Jack," the release states.
With the party's surging fortunes the New Democrats can expect to face tougher scrutiny from their opponents in the six remaining days before Canadians go to the polls, Madan said.
"Definitely the wildcard is the NDP. They could really have an enormous breakthrough or play the spoiler and upset the balance in these key critical ridings," Madan said.
In a sit-down interview with CTV Montreal Tuesday, Layton said he was not surprised by his party's surge in Quebec, saying that he had been hoping for a breakthrough in the province of his birth.
"We've been building toward this for a long time," Layton said. "I'm a guy who was born and grew up here in Quebec, so certainly it's been a dream of mine for the NDP, whose values are close to the values of the people I grew up with."
When asked if he thinks the polling numbers are believable, Layton responded with "I think they are (but) we'll see how it all comes down. Polls are polls."
The NDP's growing support in Quebec represents a serious threat to Ignatieff and the Liberals, said University of Toronto politics professor Nelson Wiseman.
"Some pollsters are saying this earthquake in Quebec is developing into a tsunami in the rest of the country and we don't know if we're going to have a nuclear meltdown for the Liberals," he told CTV's Canada AM.
Polling released on Monday by Nanos Research showed the NDP edging just ahead of the Bloc in Quebec for first place, though within the margin of error meaning the two parties were in a statistical tie.
Wiseman said an unprecedented showing in Quebec would represent a huge shift for the NDP.
"If the NDP really does make a breakthrough in Quebec and wins 30 or 40 seats it would mean more seats there than in the rest of Canada, and that's never happened and it would be a total reorientation of the NDP," Wiseman said.
He said many of the NDP's candidates in Quebec are inexperienced and are considered "sacrificial lambs" with no chance of winning. However, if the polls hold true, they could easily find themselves in government.
Layton denied that his party's candidates aren't yet ready to serve in government, saying they are from diverse professional backgrounds such as the law, teaching and community organizing.
"I'm very optimistic that we've got the right mix that will represent the full range of opinions that you find here in Quebec around the key issues," Layton said. "So I'm looking forward to having a diverse group of Quebecers around our caucus table."