Tom Mulcair got some laughs in the House on Thursday, even if the NDP leader thinks there's nothing funny about the behaviour of some Conservative senators.

Mulcair wasted little time in question period bringing up how, earlier in the day, Tory senators blocked a bid to have a key figure from the auditing firm Deloitte testify about alleged interference related to the review of Senator Mike Duffy's expenses.

Deloitte partner Gary Timm told the Senate's internal economy committee Thursday morning that Michael Runia, a managing partner, called him to inquire about Duffy's audit.

RCMP documents released last week reveal Runia made the call at the behest of Tory Senator Irving Gerstein.

Liberal Senator George Furey moved to have Runia appear to answer questions directly. But Senator Gerald Comeau, the Tory chairman of the committee, ruled against him, saying it's not their job to conduct police-style investigations.

A second vote upheld the ruling, thanks to the votes of Comeau's Tory colleagues.

Unsurprisingly, Mulcair wasn't pleased.

"Conservative senators not only blocked Conservative Party auditor Michael Runia from testifying today, they would not even allow a vote on allowing him to testify. This is the very man who Senator Gerstein illegally tried to influence to kill the Mike Duffy audit," Mulcair charged.

"Why does the prime minister have his Conservative senators blocking the testiphony..."

Mulcair pressed on after realizing his mistake.

"The testiphony, yeah!" he said to big laughs from his caucus.

"That's actually quite accurate," added NDP House leader Nathan Cullen.

But the NDP leader was able to compose himself to deliver his question.

"Why does the prime minister have his Conservative senators blocking the testimony of Michael Runia if they have nothing to hide?" he asked to a standing ovation.

Tory MP Paul Calandra shot back by resurfacing the story of an alleged bribe Mulcair may have been offered by the former mayor of Laval, some 17 years ago.

But it appears Calandra's repeated references to Mulcair's past did little to dampen the NDP leader's mood. Mulcair took to Twitter Thursday afternoon to suggest he intended to say "testiphony" all along. He even included a link to the Urban Dictionary, which defines testiphony as "testimony given that is known not to be true."

Mulcair's prosecutorial style in question period has won him rave reviews in recent months but the NDP wasn't able to turn that momentum into victories in any of Monday's four federal byelections.

Still, there is some evidence Canadians respond well when Mulcair loosens up.

Last month, an image of the NDP leader laughing directly at Harper during question period was a big hit online.

With files from The Canadian Press

Also on HuffPost:

Loading Slideshow...

  • Oh Puh-Lease!

  • You Wouldn't Like Me When I'm Angry..

  • Hide And Seek.. GO! 1.. 2.. 3.. 4..

  • Bring It!

  • No Seriously. Bring It!

  • Laser Focus

  • The World's Tiniest Violins

  • Check Yourself

  • Touchdown

  • Relax!

  • Something Isn't Sitting Right..

  • There's The Door

  • YES!

  • Who Loves Ya?

  • UP NEXT: Trudeau Glam Shots

  • UP NEXT: Memorable Trudeau Photos

  • Come At Me, Bro

    Justin Trudeau trains at Pan Am Boxing Club in Winnipeg on Friday Feb. 1, 2013.

  • Peekaboo!

    Justin Trudeau & co. making faces.

  • Riiiiip!

    Justin Trudeau splits his pants while pushing the "scrum machine" in support of Prostate Cancer Canada in Toronto Thursday, July 21, 2011.

  • Don't Shoot!

    Justin Trudeau gets his geek on at Montreal Comiccon in September 2012.

  • So Long 'Stache

    Justin Trudeau has his moustache shaved off to raise money for the Judy LaMarsh Fund, that supports female candidates, at the Liberal Party convention in Ottawa on Saturday, January 14, 2012.

  • Coming For MacKay

    Minister of National Defence Peter MacKay (left) is chased by Liberal MP Justin Trudeau in a motorized wheelchair during a wheelchair race relay on Parliament Hill in Ottawa on Wednesday, May 12, 2010. Twenty-five MPs and senators used a wheelchair for the day in support of the Canadian Paraplegic Association's Spinal Cord Injury and CPA awareness month.

  • All For One, One For All

    Justin Trudeau all dressed up for the Montreal Movember Gala in 2010.

  • Get Him!

    Pierre Trudeau's sons, Sacha, left, and Justin, tackle their mother's paperboy in Ottawa in this undated photo.

  • 'Family... And A Cow.'

    'Nuff said.

  • He Can Certainly Take A Punch

    Alexandre (Sacha) Trudeau delivers a right hook to his older brother Justin during a play fight in 1980 at Ottawa airport as the boys await a flight with the return of their father, then-prime minister, Pierre Trudeau.

  • Be Honest With Me, Who's Cuter?

    Justin Trudeau strikes a pose with an adorable baby.

  • A Very Furry Christmas

    Justin Trudeau poses with his family on his 2010 Christmas card.

  • Game On!

    Former Liberal MP Ken Dryden, left, and Justin Trudeau play table hockey as they visit Sun Youth, a community organization, Monday, Jan. 14, 2008 in Montreal.

  • Yanking Their Chain

    Then-prime minister Pierre Trudeau, left, watches as his 11-year-old son Justin swings on a chain during a tour of an old fort in the Omani town of Nizwa Dec. 2, 1983. Trudeau and Justin spent the day visiting the towns of Jebel and Nizwa 165 kilometres south of Muscat.

  • Rocking Out

    Justin Trudeau in Muskoka, Ont.

  • YeeHaw!

    Liberal MP Justin Trudeau, centre, has his cowbay taken by his son Xavier, 4 years-old, while his wife Sophie Gregoire, second from left, holds daughet Ella-Grace, 3 years-old, while they attend the party's annual Stampede breakfast in Calgary, Saturday, July 7, 2012. This is the 100th anniversary of the Stampede.

Nigel Wright, Mike Duffy ITO