He never lobbied anyone over anything. He was never in a business relationship with Nazim Gillani. He never used his wife's office improperly. He's never taken an illegal substance.

His voice at times shaking with emotion, former Conservative MP Rahim Jaffer sought to disprove a raft of allegations of misconduct involving himself and his wife, former cabinet minister Helena Guergis.

"I never did those things," he told a parliamentary committee, calling media reports "unsubstantiated allegations."

And he lambasted opposition politicians for "setting the bar at a record low, where people's lives are being destroyed on the basis of rumour and unsubstantiated allegations, for short term political benefit."

Mr. Jaffer had been accused of improperly using the resources of his wife's office for business purposes, and possibly lobbying government officials for green-energy contracts. Such lobbying would be illegal, but it never occurred, Mr. Jaffer insisted.

"We don't look to the government for anything for our work," he told the committee.

He did acknowledge that he had acted improperly on the night of Sept. 10, when he was charged with driving while intoxicated and cocaine possession. Those charges were eventually dropped and he paid a $500 fine for careless driving.

He apologized to his wife for the difficulties he caused her. "I know the error of misjudgment created significant problems for her politically," he said, his voice trembling.

NDP Pat Martin, unconvinced, asked whether Mr. Gillani gave Mr. Jaffer cocaine as "fee for services rendered."

"You have no evidence of anything and yet you're throwing out these allegations," Mr. Jaffer fumed.

Undeterred, Mr. Martin said there was no value to Mr. Jaffer's business unless it involved lobbying.

"As soon as you got the opportunity you got your nose in the trough," he accused, a charge Mr. Jaffer strongly denied, saying the NDP MP had turned the hearing into "a circus."

And Mr. Jaffer denied allegations he had used his wife's office to promote his own business.

"I never abused parliamentary resources...nor would I abuse my wife's resources in any capacity," he said. He simply used her office while he was clearing out his own after being defeated in the October 2008 election, he said.

There were guffaws of disbelief when Patrick Glémaud, Mr. Jaffer's business partner, said he could "not recall" the names of firms he submitted to Tory MP Brian Jean, parliamentary secretary connected to the Transport Minister with oversight of infrastructure spending.

Mr. Martin said of Mr. Glémaud that "I don't believe you far as I can throw you."

The committee gave Mr. Glémaud 24 hours to produce the names.

Mr. Jaffer went on to deny that he had any business dealings in Belize, contradicting media reports.

The parliamentary committee is ostensibly examining whether there were any improprieties in how Mr. Jaffer and Mr. Glémaud, conducted their green-energy consulting business.

Mr. Jaffer's own Conservative colleagues questioned statements on his personal website that seemed to suggest he could use his political connections to secure business for clients.

"We are held to higher standards," Tom Lukiwski said. "Do you believe the appearance of propriety has been tarnished?"

"The only thing I can say to you is that I personally feel that wasn't our intention," Mr. Jaffer replied.

Follow Mr. Jaffer's testimony live in the panel below: