If the Trudeau government has any hope of seeing the back of the SNC-Lavalin scandal, it has to put its full version of the story, all of it, in front of the Canadian people.

Prime Minister Justin Trudeau has to make his case, and he has to do it now.

Perfunctory denials won’t do. The allegations made by former justice minister and attorney-general Jody Wilson-Raybould are too serious. That the allegations go to the very top, and come from one of the government’s most senior members, makes them unprecedented.

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The fact that the Prime Minister’s former principal secretary, Gerald Butts, is to appear next week before the Commons justice committee is a good start. The fact that several other senior officials named by Ms. Wilson-Raybould have not been asked to appear at the Liberal-dominated committee is not.

And then there’s how, in her appearance this week, she hinted that she might have much more to say, if and when restrictions placed on her by cabinet confidentiality are fully removed.

When the narrative gets to wherever it is going, it will be up to Canadians to judge, at the ballot box. The election is scheduled for October, but given that one day can be a long time in politics, fall might as well be in another century.

The irony and tragedy of it all is that, until three weeks ago, the Liberals were cruising to re-election. The reasons, obvious to everyone, may have been less plain to them.

“We can have the best policy in the world,” senior Prime Minister’s Office adviser Mathieu Bouchard allegedly told Ms. Wilson-Raybould in one of the many attempts to persuade her to intervene in the SNC-Lavalin prosecution, “but we need to get re-elected.”

Getting re-elected, in this telling, was not about the good policy on display in the well-lit front window. It was about the shady transactions out the back door.

But Liberal policies, combined with a bit of luck in terms of the poor state of the opposition and the good state of the global economy, were what stood behind the cakewalk re-election that might have been. The group that Mr. Trudeau always claims to be all about – “the middle class and those working hard to join it” – has mostly had a pretty decent run these past few years.

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For example, on Tuesday, Statistics Canada revealed that the country’s child-poverty rate fell, again. It hit a recent peak of 15 per cent in 2012, but it’s now down to just 9 per cent. That’s thanks in part to a signature Liberal policy, the Canada Child Benefit, which has boosted the incomes of middle- and lower-income families with children.

The number of families of all types living in poverty fell, down to 9.5 per cent in 2017 compared to 10.6 per cent in 2016. Poverty among seniors fell to just 3.9 per cent.

Unemployment is at lows not seen since the 1970s; incomes are rising for the middle class. The Liberal government inherited much of the good news, but it could claim its share, and polls suggested that was likely to get it returned to office in October.

The high road was Mr. Trudeau’s straightest route to the desired destination of re-election. If he and his senior officials have detoured from it, they may have put their futures in jeopardy.

Canadians will be the final judges of all of that. But before they pass sentence at the ballot box, others may yet act.

The list of those holding shoes that may drop includes Mr. Trudeau’s weirdly passive caucus. Ms. Wilson-Raybould revealed many things this week, and one of them is that, while a PM appears all-powerful, with members of Parliament elevated to a ministry at his pleasure and kicked to the backbenches at his displeasure, he can be challenged and cut to the core by those same MPs.

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In the Canadian system, MPs tend to act like junior employees of the PMO. But in other parliamentary systems, it’s very different. In Britain, the MPs of a governing party will not hesitate to replace a PM who imperils their electoral chances.

How this plays out in Ottawa depends on how Mr. Trudeau responds. He’s got to convince Canadians that he did nothing wrong. He may also be able to admit wrongs, yet somehow make them right.

He has time, but it is fast running out.