Did Justin Trudeau threaten to demote Jody Wilson-Raybould from the role of attorney-general unless she intervened to protect SNC-Lavalin from prosecution on corruption charges? The RCMP would like to know, and so would every Canadian.

But this government refuses to release those involved from their oath of secrecy, frustrating the police inquiry and the public will. And so the time has come for Ms. Wilson-Raybould and Jane Philpott, her friend and former cabinet colleague, to tell Canadians what they know about the cabinet shuffle that eventually led to their resignations.

Mr. Trudeau and his advisers are hiding behind the convention of protecting cabinet confidences. They must not hide any longer. The national interest dictates that Canadians cast their ballots in this election with full knowledge of what happened behind those very closed doors. It is time for everyone to speak their truth.

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To recap very briefly: When The Globe and Mail revealed in February that Mr. Trudeau and his advisers had pressed Ms. Wilson-Raybould, who was then attorney-general, to intervene in the criminal prosecution of SNC-Lavalin, the former minister asked to be released from her oath to protect cabinet confidences so that she could tell the Commons justice committee what had happened.

Mr. Trudeau did provide a waiver, but it did not extend to conversations and events surrounding the cabinet shuffle that removed Ms. Wilson-Raybould from the role of attorney-general. Ms. Wilson-Raybould expressed her frustration with that decision, and so did Ethics Commissioner Mario Dion, when the government refused his request to examine witnesses about the cabinet shuffle and other matters.

As Robert Fife and Daniel Leblanc reported Tuesday, the RCMP also wants to know what was going on during that shuffle, as part of an examination into whether anyone might have obstructed justice. But that inquiry has been blocked by the government, which again refuses to waive cabinet confidentiality for all witnesses.

Ottawa blocks RCMP on SNC-Lavalin inquiry

Government officials insist that the Clerk of the Privy Council, who is the head of the federal public service, and not anyone in the Prime Minister’s Office made the decision not to co-operate with the RCMP.

“We respect the decisions made by our professional public servants,” Mr. Trudeau told reporters, curtly, outside Rideau Hall in Ottawa, Wednesday. "We respect the decision made by the Clerk.”

Sure.

Here is one possible truth: When Ms. Wilson-Raybould refused to let SNC-Lavalin off the prosecutorial hook, Mr. Trudeau decided to rid himself of his turbulent minister by means of a cabinet shuffle.

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Maybe there was a conversation between Mr. Trudeau or one of his advisers and Ms. Wilson-Raybould. Maybe that conversation was heated. Maybe someone explained to Ms. Philpott that Ms. Wilson-Raybould was being demoted because she wasn’t a team player. Maybe, in other words, there was obstruction of justice.

Or maybe there wasn’t. Maybe nothing like that happened at all. All we know is that the Liberals have gone to extraordinary lengths to keep people from speaking. They blocked the justice committee that looked into the affair. They blocked the Ethics Commissioner. And now we know they blocked the RCMP.

But an election campaign is under way. People must know the truth before they cast their ballot. They must know why the Liberal Leader refuses to release his cabinet colleagues from their oath and why he is stonewalling whenever reporters ask him about it.

Of course there are other issues that matter as well. Which party can be trusted to rise to the challenge of global warming or to a possible recession? What approach should the next government take to a belligerent China or to the Trump administration?

But above all, this election is about trust: Who should voters trust to lead this large, prosperous but fractious country in the years ahead? Before we can answer that question, we have to know what Mr. Trudeau is hiding from Parliament, the Ethics Commissioner, the police and us. We have to know whether we can trust him.

And if he won’t tell the truth, those who know the truth must speak, even if it means breaking cabinet confidence. The national interest demands it, and that comes before all.

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