Anger shot through Stephen Harper the moment he learned Nigel Wright, his wealthy chief of staff, had reached into his own pocket to pay Senator Mike Duffy's disputed expenses, but that outrage didn't stop Harper from wishing Wright well before he testified at Duffy's trial.

Those revelations are included in an exclusive interview with CBC News airing Monday evening on The National.

Harper makes it clear he believes Wright and Wright alone was responsible for keeping him in the dark about the plan to repay Duffy's $90,000 expenses from his own funds.

"There's no person on my staff that I believe deceived me or acted unethically or irresponsibly," the Conservative leader said. "Other than Mr. Wright."

That flies in the face of testimony at Duffy's trial last month that showed Benjamin Perrin, former legal counsel in the Prime Minister's Office, and Harper's current chief of staff, Ray Novak, were among several senior officials who were informed of the plan.

The Conservative government presented a vastly different version of events to Canadians for at least two months in 2013. That version had Duffy paying for his own expenses.

'You have to move on'

Testimony at the senator's trial this summer suggests that strategy was invented to contain a ballooning political problem that was toxic to the Conservatives' brand of fiscal rectitude.

Harper said he was indignant when he learned in May of 2013 that the problem had been dealt with by dipping into Wright's personal funds.

"I went through a period where I was very angry. But you've just got to let that anger go. You have to move on."

Conservative campaign officials acknowledge the Duffy trial derailed much of the early phase of the Conservative election campaign in the month of August. Harper's daily attempts to unveil new policy were swamped by testimony emerging from the trial that seemed to support Duffy's contention Canadians had been deceived by the highest-ranking members of Harper's team.

But Harper is having none of the suggestion that he fire Novak or anyone else in his government who might have been involved in this deception. He defended his staff and pointed to controversial show hosts fired by CBC to defend his position.

Indignation to a certain point

"When you have problems with Jian Ghomeshi or Evan Solomon, you don't go around firing everybody who worked for them. That's not the fair thing to do," Harper said.

Nigel Wright was the one person who was forced out of the PMO. Wright has testified his decision to pay for Duffy's expenses was made out of charity as well as a desire to contain a political problem, but his actions had the unintended consequence of bringing the scandal directly into Harper's inner circle.

Harper has accused him of deception and unethical behaviour in office. But the Conservative leader's indignation only went so far. He did reach out to speak to Wright at least once after his embarrassing exit.

"We had, I think, one very brief conversation," Harper said. "It was just after he took a job in London and I wished him well."

The interview, covering a wide range of issues, can be seen Monday night on The National at 9 p.m.ET on CBC News Network, and at 10 p.m./10:30 NT on CBC-TV. It is the first of four interviews with the federal leaders airing this week — read more about the interviews here.