The PMO's former lawyer says he thought the prime minister had fully signed off on a plan to have Mike Duffy's outstanding Senate expenses paid off by someone else, an Ottawa courthouse heard Friday at the senator's criminal trial.

Benjamin Perrin testified that he thought the prime minister had "personally approved" a plan to pay back Duffy's questionable Senate expenses for him, with Duffy agreeing to publicly admit to a "possible error" in his paperwork.

Perrin said he got that impression from an email sent by Nigel Wright, Harper's former chief of staff, on Feb. 22, 2013. The email in question, which was submitted into evidence last week, included Wright's much-discussed words: "We are good to go from the PM."

Wright testified last week that "good to go" meant Harper was aware the expenses would be paid without taxpayer money – not that they would be paid by someone other than Duffy himself.

Perrin interpreted that phrase differently at the time, he told the court. He said he thought Harper had given the go-ahead to a "five-point plan" he and Wright had hammered out with Duffy's representative at the time, which included a point to keep Duffy "whole on the repayment." He said that at the time, he thought Wright was "explicitly" speaking for the prime minister in his role as chief of staff.

Perrin also told the court he felt "blindsided" a month later, when he learned that Wright had agreed to cover Duffy's expenses with a personal cheque for $90,000. Perrin said he learned about the cheque on March 22, 2013, ahead of a conference call between PMO staffers and Duffy's representative.

Perrin insisted that Harper's current chief of staff, Ray Novak, was present for that conference call on March 22, contradicting testimony from Wright earlier in the trial.

Perrin told the court he specifically remembered Novak being in the room for the call.

Wright was fired when the secret payment came to light, but Perrin's testimony has raised questions about how much Novak knew about the deal. On Thursday, Perrin told the court Novak was made aware of the $90,000 payment on at least two occasions.

Duffy's deal

Defence lawyer Donald Bayne wrapped up his cross-examination of Perrin on Friday afternoon, after the Crown concluded their questioning earlier in the day.

Bayne questioned Perrin about Duffy's reluctance on Feb. 20, 2013, when the senator was putting up resistance in his negotiations with the PMO.

"He was not interested in voluntarily repaying at the time," Perrin told the court. "Senator Duffy didn't want to repay."

Perrin said Duffy's lawyer spoke to Wright that night, but Perrin was "kept in the dark" about their conversation.

Perrin also characterized Duffy's negotiation points as a list of demands.

"That's how it was impressed on me, that these were demands," he said.

The Crown asked Perrin about several emails submitted as evidence last week, which appear to show Perrin and Duffy's lawyer hammering out terms for the repayment deal. An email from March 25, 2013 shows Duffy's representative asking for an "assurance" that Conservative-appointed senators be urged to vote against any motion to refer Duffy "for further investigation or action by Deloitte, the RCMP or any other party."

Perrin told court on Friday this was the first time anyone explicitly suggested not referring the matter to the RCMP. He added he had detected no "whiff of criminality" up to that point, and if he had, he said he would not have agreed to it. "If pushed by Wright, I would have gone to the PM. If pushed, I would have been obliged to resign, because it would have been unethical," Perrin told the court.

He added he convinced Duffy's lawyer to drop the RCMP from her proposed wording, because he felt the "any other party" line "was sufficient broad language."

Questions about Novak

The trial has been a headache for the Conservatives' election campaign, and a constant thorn in Stephen Harper's side when addressing reporter questions over the past few weeks.

Novak was Harper's principal secretary at the time of the Duffy deal, and is considered one of his close confidants.

A string of emails submitted as evidence last week appear to show that Novak was part of the PMO conversation about how to deal with Duffy's repayment, while keeping it out of the public eye. Among those emails was one sent from Wright to Novak and Perrin on March 23, 2013, which read: "I will send my cheque on Monday."

Novak is a key member of Harper's re-election campaign, but he has been noticeably absent from the Conservative Leader's side since his name started coming up in court.

Harper has not addressed Novak's situation directly, but he did say on Thursday that anyone working for him has his "confidence."

"If they didn't have my confidence, they wouldn't be working for me," Harper told reporters in King Township, Ont.

He also insisted once more that Duffy and Wright were the only ones to blame. "I have held the two people accountable who are responsible," he said. "I'm not going to go around holding everybody else accountable for their actions."

Duffy has pleaded not guilty to 31 charges, including fraud, bribery and breach of trust.

Perrin's testimony is done, and court is adjourned until Monday.