Mike Duffy trial subpoenas former Sun News host Ezra Levant

Ezra Levant and Sen. Mike Duffy have appeared on each other's talk shows over the years — now they'll both be featured in one of the year's most-watched courtroom dramas.

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Levant, the provocative political commentator formerly of Sun News, has been subpoenaed to testify at Duffy's upcoming fraud and bribery trial.

Levant confirmed to The Canadian Press that he's been summoned as a Crown witness for the case that begins in an Ottawa court April 7.

Levant, also a lawyer and columnist, said he wrote "a couple" of speeches for Duffy five or six years ago. He declined to comment on the subject matter of the speeches.

"...Out of respect for the court I don't propose to give my testimony in advance," Levant said an email.

Duffy is facing 31 charges of fraud, breach of trust and bribery.

Unclear how Levant fits into Crown case

The Mounties described one series of breach of trust charges as relating to "the awarding of consulting contracts over a four-year period, and subsequently using part of the funds from those contracts for personal gain or for expenses which circumvent Senate oversight."

It is unclear, however, how Levant's work for Duffy fits into the Crown's case.

His name has not appeared in any court documents related to the Duffy trial, unlike those of other contractors.

When Levant is scheduled to appear in court is also unknown.

The trial is expected to start with a lengthy examination of Senate finance rules and paperwork.

Before Levant began work as a talk-show host on the Sun News network, he appeared a handful of times on Duffy's own political panel on CTV News.

Duffy was appointed to the Senate by Prime Minister Stephen Harper in January 2009, and appeared on a number of occasions in that capacity on Levant's Sun News program "The Source."

Levant commented on the Senate expenses scandal that embroiled Duffy in the fall of 2013, after the RCMP had first filed a description of their allegations in court.

At that point, the police were still eight months away from laying charges, but were seeking a production order for more records.

Initial police documents 'unproven gossip': Levant

Levant referred to those first police documents as "hundreds of pages of unproven gossip, second- and third-hand information and just plain hunches."

"So what are cops to do? They could keep investigating, or try waiting until some new fact comes to light," Levant wrote in a column for Sun News.

"Or they could accept their suspicions were wrong ... Stephen Harper, Nigel Wright, Duffy and the Conservatives might not be to everyone's taste, and might even have ethical problems, but they have done nothing approaching the turpitude of a criminal offence."

Police did not charge Wright, Harper's former chief of staff, who secretly gave $90,000 to Duffy in early 2013 so the senator could repay contested living and travel expenses.

Instead, police have alleged Duffy engaged in bribery and fraud in his dealings with Wright.

Duffy has maintained his innocence throughout, and said he was the victim of a political scheme concocted inside the prime minister's office to force him into repayment of expenses.

Duffy felt the expenses were within the rules, and said he had been told as much by Wright and other Senate officials.

"We are confident that when the full story is told, as it will be, and shown to be supported by many forms of evidence, it will be clear that Sen. Duffy is innocent of any criminal wrong-doing," read a statement released when the charges were laid.