The Opposition leader apologized for what he termed a "misunderstanding" after breezing through a security checkpoint, where a new guard didn't recognize him, and being followed to his parking spot by the Mounties.
No warnings or citations were issued and Mulcair insisted his exchanges with police officers during the incident were entirely "respectful."
But that's pretty much where respectful ended: Conservatives in the House were quick not only to mock the NDP leader, but to use the incident as a political hammer.
Heritage Minister James Moore, standing in for the travelling Prime Minister Stephen Harper, said the incident demonstrates Mulcair "does not have the temperament to be the prime minister of Canada."
Statements by Conservative MPs and answers during the House of Commons question period were sprinkled with references to Mulcair and allusions to his alleged temper.
Mulcair was absent from question period.
"I would like to answer the NDP leader's real question from today," said Moore, who seemed to delight in recounting the incident to a raucous Commons. "He asked the question: 'Do you know who I am?'
"Turns out we know who the NDP leader is. He ran through five stop signs, as reported. He refused to pull over to the RCMP when they asked him to pull over. And then when he was finally confronted by an RCMP officer, he said to her: 'Do you know who I am?'"
Conservative MP Candice Bergen said the incident shows Mulcair's "complete lack of judgment." And International Co-operation Minister Julian Fantino, a retired police officer, called the incident an insult to police.
However, in an interview, the NDP leader refuted the Conservatives' version of the events, which he deemed a desperate attempt to deflect attention from the Senate expense scandal that has rocked Parliament throughout the spring.
"Anything to change the channel," Mulcair told The Canadian Press.
"Basically, what happened this morning is I did what I do every single morning when I come to Parliament. I go to the same gate, I wave to the people who are on duty and then I just drive slowly, being careful, up to my (Centre Block) office."
Thursday morning, however, a new guard was on duty at the checkpoint and she didn't recognize Mulcair.
"I waved. I thought I got a wave back but I didn't so we wound up having the slowest promenade in front of the building. I went around the back (followed by) another officer who'd been dispatched to see who it was. The other officer was able to verify my identity and that was it."
A while later, Mulcair said he went back to the checkpoint to clear up the misunderstanding.
"When I went back and talked to her, she was apologetic and I apologized myself for the misunderstanding. I didn't want the misunderstanding to last. She felt bad, I felt bad, we shook hands and that was the end of it."
As for running multiple stop signs, he said: "That's not true at all."
Mulcair also denied asking the officer who followed him to his parking spot if he knew who he was.
"The officer asked me who I was and so I identified myself. It was a very polite exchange," he said.
"One of my sons is a 12-year police officer and I'm always very respectful with the police, including today."
Conservatives didn't wait to hear Mulcair's version of events before pouncing on reports about the incident.
As a New Democrat MP spoke to reporters outside the House following question period, Ontario Conservative MP Greg Rickford held up a photocopied, paper stop sign that read: "Stop Mulcair."
The incident was used as a shield when it came time to ask about news that the RCMP has launched an investigation into the $90,000 cheque Prime Minister Stephen Harper's former chief of staff wrote to bail Sen. Mike Duffy out of the housing expense scandal.
Moore responded to a question on Wright with a few questions of his own for Mulcair.
"Is the leader of the NDP being investigated for running five stop signs?" Moore asked.
"Is the leader of the NDP being investigated for not listening to an RCMP officer? And is the leader of the NDP at some point going to show up in this House and apologize to Canadians for breaking the law?"
In 2010, Conservatives were on the receiving end of similar barbs when Ottawa MP Pierre Poilievre drew the wrath of the RCMP after he blew past a Parliament Hill checkpoint.
At the time, Foreign Affairs Minister John Baird described that incident as "trivial." New Democrat stalwart Pat Martin told the Commons that Poilievre "should throw a bag over his head on Parliament Hill for behaving like that."
Not to be left out on Thursday, the Liberals proposed a motion urging the Commons to not only recognize the service the RCMP provides on the Hill, but also to remind members and staff of traffic regulations.
It passed unanimously.
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