During a bitterly fought by-election campaign in Montreal, an NDP supporter aimed a video camera at the Liberal headquarters. The recorder spied on Liberal volunteers tearing down an NDP sign on the street, and the images were sent along with a complaint to Elections Canada, and shared with a reporter at Sun Media.
The incident captured the increasing bitterness between the two opposition parties, which culminated with Liberal Leader Justin Trudeau's speech after his by-election victories in the ridings of Bourassa and Toronto-Centre.
"This is no longer the hopeful, optimistic party of Jack Layton. It is the negative, divisive party of Tom Mulcair. Because it's the Liberal party, tonight, that proved that hope is stronger than fear, that positive politics can, and should, win out over negative," Mr. Trudeau said Monday night in Montreal.
The line railed New Democrats, which called the reference to the former NDP leader "offensive" and hypocritical. Mr. Mulcair will react to his party's by-election results Tuesday afternoon, but his team is already in a bitter mood.
"Instead of winning graciously, the Liberals threw out a few lines from a deceased man to score political points," an NDP strategist said in an interview. "That's far from positive politics."
The NDP said the Liberals have accused Mr. Mulcair of being "too angry" during the by-elections and raised questions about the NDP's federalist convictions, proving that they are also playing hardball politics, contrary to their leader's statements.
But the Liberals are continuing to promote themselves as the positive alternative to the Conservative Party, fresh from the by-election victories in Montreal and Toronto, and a strong showing in the riding of Brandon-Souris in Manitoba.
"The Conservative vote has fallen in all ridings and they have been punished by the electorate, but the party that has reaped the rewards is not the Official Opposition – the 'government-in-waiting' as Mr. Mulcair likes to portray his party – but the Liberals," said Robert Asselin, a senior adviser to Mr. Trudeau.
Mr. Asselin added the NDP is playing a "dangerous game" with its attack ads that are reminiscent of recent Conservative negative campaigns.
However, the NDP strategist said that the party's goal was to find a creative way to engage the electorate in a busy political season and "make the Liberals sweat" in their two urban strongholds.
"We had to shake something loose," the strategist said. "We succeeded in putting them on the defensive."
Mr. Mulcair, who took over the reins of the NDP in 2012, made frequent stops in Bourassa and Toronto-Centre during the writ period. Instead of waging a low-key fight, Mr. Mulcair and his party raised the stakes by launching a series of attacks against Liberal candidates Emmanuel Dubourg and Chrystia Freeland.
The fight was especially bitter in Bourassa. On Nov. 12, the NDP put up a series of signs in the riding that attacked the "Club Privilège Libéral," accusing Mr. Trudeau's candidate of having abused the public purse by taking a $100,000 allowance to quit his seat in the National Assembly to run on the federal stage. It was one of those signs that the Liberals brought down just in front of their campaign office during the campaign.
On Monday night, however, Mr. Dubourg took 48 per cent of the vote to easily hold on to Bourassa for the Liberal Party. The riding had been Liberal since 1997, but the party faced a big test after long-time MP Denis Coderre left earlier this year to run in Montreal's mayoral race.
The NDP proclaimed that its candidate in the riding was a star – Stéphane Moraille sang in a band called Bran Van 3000, was born in Haiti (like many residents in the riding) and had a strong career as a lawyer. However, she finished with 31 per cent of the vote – a one-point drop from the party's showing in the riding in the 2011 general election.
Still, the aggressive NDP campaign suggests Bourassa was only the first skirmish in an increasingly tense battle for votes in Quebec. There was much bitterness between New Democrats and Liberals in Bourassa, which will reverberate among partisans and organizers throughout the province.
On the national stage, the NDP is hopeful that Mr. Mulcair's strong performances in the House of Commons, holding Prime Minister Stephen Harper's feet to the fire over the Senate scandal, is the party's priority at this point.
"Over the long term, it will bear fruit," the NDP strategist said.
Daniel Leblanc is a parliamentary reporter in Ottawa.