Is anyone telling the truth in the getting-worse-by-the-day Senate scandal?

Disgraced Mike Duffy launches a vitriolic tirade against the prime minister and his office, in which he claims Stephen Harper told him to repay improperly claimed expenses. Harper acknowledges doing that, but says he knew nothing about the $90,000 payment from his chief of staff to Duffy, intended to repay the expenses. Duffy alleges Harper's current chief of staff, Ray Novak, knew about the payment and is involved in the "monstrous political scheme." Duffy, highly-paid retired journalist and senator, incredibly claimed he didn't have the money to repay the expenses.

Senator Pamela Wallin takes the stand and claims that rules were changed for the purpose of inflaming public opinion against her, that she is the victim of a Conservative campaign that has "left her reputation in tatters." She also says she was ordered to resign from the Conservative caucus by the same Harper staffer.

Harper and his closest supporters won't address the broader allegations about his and the PMO's involvement. They will only defend him for ordering the repayment.

That position has been tenuous from the start and won't wash any longer. Harper needs to tell Parliament everything he knows about the whole affair. He should release any relevant records. He needs to come clean and do so as soon as humanly possible.

He should do this because it's the right thing for a credible national leader to do. But he should also do it because only full disclosure will make this go away. His office's strategy on managing the crisis so far is a dismal failure. Over nearly a year, it has changed stories, stonewalled, and tried to deflect to other news. Nothing has worked.

Even if he does that — and given his track record it's not likely — the damage already done is considerable. His personal credibility is hanging by a thread. The scandal is so big and dirty, it will prevent him from accomplishing a major commitment: Senate reform. Whatever moves he makes on that file now are bound to look like more dodging and weaving to keep him and his office from being directly linked, not only to the scandal but to how the Harper Conservatives have mismanaged it since the story broke 11 months ago.

The allegations made by the disgraced senators are deadly serious. They claim the PMO is managing the investigative and discipline process, interfering in the Senate's operation, and doing it all for political reasons that have nothing to do with hearing all sides of the story and then rendering a fair decision.

Typically, Canadians don't care much about the Senate. They care now, and for all the wrong reasons. Never mind abolition. Bring in the cameras and sell tickets. You can't make this stuff up.