Ottawa is a city of leaks.

It can be one of the more charming qualities of the place.

Leaks are often grease for the gears of government, providing grist for reporters, lobbyists and politicians.

But there are leaks, and then there are leaks.

One of the most curious aspects of the criminal investigation involving Vice-Admiral Mark Norman — whom the RCMP suspects of breach of trust and disclosing cabinets secrets — is the notion that one particular leak, involving the navy's deal to acquire a temporary supply ship, stood out among all of the other leaks that flood Canada's capital on a weekly basis.

Case in point: No eyebrows seem to have been raised when specific details about how the recent federal budget would promise, but not deliver, cash for veterans' pensions made their way into the public domain.​

Federal budget information is supposed to be among the most closely guarded of cabinet secrets — or it used to be.

So, what is it precisely about the Nov. 20, 2015, shipbuilding leak to the media that so angered the Liberals?

Why were they upset their review of the $660-million supply ship project at Quebec's Chantier-Davie Shipyard had become public?

Was it the fact the deal was cut by the Conservatives on the eve of the 2015 election?

Was it the fact the Harper government literally rewrote the regulations governing sole-source purchases in order to make it happen?

Was it because the shipyard is in the riding of then-Tory cabinet minister Steven Blaney?

Hands tied

A clue is found in the interview Treasury Board President Scott Brison gave to the RCMP where he described how the leak apparently prevented a cabinet sub-committee and the government as a whole from doing its job.

"The rendering of this [classified information] into the public domain did an awful lot to limit our ability to really do what [the committee] intended to do, and that is more due diligence on this," Brison is quoted as saying in a heavily redacted search warrant used to seize Norman's cellphone and electronics.

Treasury Board President Scott Brison says the leaks surrounding the navy's sole-source deal to acquire a temporary supply ship limited his government's ability to do its 'due diligence' on the purchase. (Adrian Wyld/Canadian Press)

It's not clear from the redacted document whether Brison, the Liberals' political minister for Nova Scotia, explained why cabinet felt its hands were tied.

The project was cleared to proceed days after news of the review became public, and the supply ship will be delivered in September.

But what was it about the sole-source arrangement that the newly elected Liberals wanted to ponder before signing off?

Political interference?

The easy, reflexive, politically-incendiary answer — the one many gravitated towards — is that Irving Shipbuilding leaned on the Liberal government, which had just swept Atlantic Canada.

It was through that lens that some of the first leaked stories were framed.

Irving had written to Defence Minister Harjit Sajjan and Public Works Minister Judy Foote asking for a review of the Davie project. The message was delivered just days before the cabinet committee put the project on hold.

The letter was also copied to both Brison and Finance Minister Bill Morneau.

It's also worth noting that, based on the way it appears in the RCMP search warrant, a staffer in Brison's office seems to have been the one who twigged to the leak of cabinet secrets after the first stories appeared.

Last week, Irving issued a statement to CBC News and the Globe and Mail, which succeeded in a court fight to unseal the search warrant in the Norman case.

Kevin McCoy, president of Irving Shipbuilding Inc., suggested the timing of the letter was coincidence and not based upon any forewarning that cabinet was about to give its final approval on the Chantier-Davie project.

Kevin McCoy, president of Irving Shipbuilding Inc., says the purpose of the company's outreach to the newly elected Liberal government was simply to highlight its concerns about the supply ship deal and to request that its proposal be evaluated fairly. (Andrew Vaughan/Canadian Press)

"We expressed those concerns to the new government as part of an ongoing transparent dialogue," McCoy said.

Email correspondence between Norman and a friend that was leaked to the media when the search warrant was partially unsealed suggests the vice-admiral believed otherwise on the day the stories first appeared.

Irving Shipbuilding "aided and abetted by [redacted] have been looking for an opportunity to torpedo the Davie solution for sometime," says the note from Nov. 20, 2015. "My sense is that [Irving Shipbuilding] post election has significantly more political clout and are prepared to use it."

But McCoy's recent statement denies that: "Our outreach to the newly elected Government of Canada highlighted our concerns and requested that our proposal be fairly evaluated."

What he's referring to is the attempt by Irving — and other shipyards — to bid on the navy's temporary supply ship, the contract delivered to Chantier-Davie through an extraordinary sole-source deal.

Unanswered questions

All of the fog and thunder surrounding the RCMP investigation of Norman and the leaks of cabinet secrets seem to have obscured questions about why the Conservatives took extraordinary steps to secure the deal in the run-up to the last election.

For example — as The Canadian Press reported in August 2015 — cabinet had to sign off on an unprecedented change to the regulations governing sole-source purchases in order to make the deal happen.

The effect of that was to cut the federal Treasury Board, which holds the purse strings, out of the loop, according to federal officials who asked not to be named.

CBC News has learned that the RCMP is investigating an alleged information leak by suspended Vice-Admiral Mark Norman 2:18

When the Liberals came to power, the bureaucracy couldn't tell its political masters what value-for-money taxpayers were getting from the Chantier-Davie deal.

What they could say was the procurement didn't follow the established rules and a total of six companies had expressed interest and some — including Irving — submitted lower preliminary cost estimates.

Why did the Conservatives choose to ignore the other bids and negotiate directly with Chantier-Davie?

Was this what the Liberals wanted to ponder? Were they afraid they had been left some kind of potential scandal by the Conservatives that would tarnish Prime Minister Justin Trudeau in Quebec?

Neither Brison nor anyone else in the government that promised transparency will address those questions.