Nigel Wright is in the clear. His decision last year to repay $90,000 in improper expenses claimed by Senator Mike Duffy may well be regrettable, ill-advised and even damned foolish. But it was not criminal.

That's the good news for Nigel Wright. It bodes well for Prime Minister Stephen Harper, who could have been called to testify as a witness if his former chief of staff had been charged.

And it reduces the chance that the now suspended Senator Mike Duffy will be charged with breach of trust, although legal troubles hang heavy over his decision to claim the living and travel expenses in the first place.

The RCMP have confirmed Prime Minister Stephen Harper's former chief of staff, Nigel Wright, won't face criminal charges over a $90,000 payment to suspended Senator Mike Duffy. Harper, left, 'dismissed' Wright last May when word of the payment got out. (Prime Minister's Office) The bad news is Wright remains responsible for his own decision. As the chain of emails he voluntarily turned over to investigators reveals, the prime minister's top adviser devoted far too much time and energy to trying to get Duffy to repay those impugned expenses.

He offered Duffy assurances that the Deloitte auditors would go easy on him in their review, and that the party's leadership would endorse Duffy's claim to remain a senator from Prince Edward Island.

Wright even asked the head of the Conservative's fundraising arm, Senator Irving Gerstein, if the party would repay Duffy's expenses. Gerstein said yes, at first, until he and Wright learned the true amount wasn't $32,000 but nearly three times that amount.

The drawn-out negotiations between Wright and Duffy, the involvement of members of Wright's staff, leading Conservative senators and ultimately lawyers for both the prime minister and the now-suspended senator are hardly the heady stuff of government. They are actions that take place in the trough of patronage and entitlement. They speak to an overarching need to protect the government from scandal.

Wright's actions may not have been deemed illegal, but they were troublesome enough to inflame a scandal that will continue to stalk this government.

The impact on his personal life is equally severe.

Wright's been in legal limbo, and political purgatory, ever since his fateful decision to dig into his own pocket for Duffy became public. His formidable reputation, built over years in business and political circles, has been undercut on a near daily basis in question period — a place where anything can be said and used against you, a place where the right to a fair hearing, or even to tell your side of the story, is never guaranteed.

And then there's the ethics commissioner, Mary Dawson, who confirmed Tuesday that she is restarting an inquiry suspended last June when the RCMP began its criminal review of the Wright-Duffy affair.

What about Duffy?

Sources tell CBC News that Wright may still be called as a witness in future court proceedings, and that he will continue to co-operate fully.

Mike Duffy, suspended without pay by the Senate in November for claiming ineligible expenses, still faces investigation for fraud over the claims. (Reuters) CBC News has also learned that investigators and the Crown attorney assigned to them decided weeks ago not to pursue a criminal charges against Wright. It's not clear why they delayed making that public until Tuesday, other than concern that the information might in some way prejudice the simultaneous probe of Duffy.

With Wright now cleared, the obvious question is what happens to the criminal investigation against Duffy. In other words, if the evidence doesn't support charges that Wright tried to bribe or influence Duffy by repaying his expenses, how can Duffy face similar charges for accepting the cash?

Duffy gave a vigorous defence of his actions in the Senate last October, before he and fellow Conservatives Patrick Brazeau and Pamela Wallin were suspended from the upper chamber without pay over their expenses.

In that speech, Duffy used all his skills as a story-teller. He accused the "boys in short pants" in the Prime Minister's Office of being the masterminds of a "monstrous political scheme."

He said he was forced to read a script written for him, against his will, against his own deeply-held conviction that he had done nothing wrong in claiming a housing allowance, and money for meals he'd eaten in his Ottawa-area home.

He recast himself from villain to victim. But he's never reimbursed a cent with his own money. The investigation into his actions continues.

The prime minister's role

And what of Stephen Harper's own role in this affair.

The Prime Minister's Office put out a statement Tuesday saying it was pleased with the progress made by the RCMP, and promising to offer all possible assistance to the force.

NDP Leader Tom Mulcair says he knows where Harper can start.

"I don't think it put any ring around Mr. Harper, who has refused to give clear answers to very simple, clear questions in the House, and the few times that he has given answers, he's contradicted himself from one day to the next," Mulcair told the CBC's Evan Solomon.

"I think Canadians still have a right to know exactly what went on, what the prime minister knew and when he knew it."

Harper insists he has. He's said, repeatedly, that he first learned of Wright's repayment on May 15. The Mounties have said, repeatedly, that Harper is not under investigation.

Still, there is one troubling email thread among the thousands Nigel Wright voluntarily turned over to police investigators, dated Feb. 22, 2013, in response to Duffy's demands, including one "to keep him whole on the repayment."

In an exchange of messages, Wright tells colleagues he wants to speak to the PM before the deal is finalized. An hour later, he sends another email indicating "we are good to go from the PM."

The prime minister insists "good to go" meant he approved of Duffy repaying the expenses, himself.

The opposition didn't buy it then. And one expects they'll be good to go on what the prime minister knew when the House resumes after the Easter break.