Just how much the Harper government trusts National Defence in the wake of the F-35 fiasco was drawn into question Tuesday.

Defence Minister Peter MacKay acknowledged he's not sure who will carry out an independent analysis of the stealth fighter program.

The frank confirmation came on the same day Public Works Minister Rona Ambrose suggested it could be months before the latest price estimate for the radar-evading jet is tabled for public consumption.

In the wake of a scathing report April 3, in which Auditor General Michael Ferguson accused National Defence of hiding the true cost of the plane, the Harper government promised to release an updated figure within 60 days.

That hasn't happened, and Ambrose said it won't until she's satisfied with the numbers.

"We will not table cost estimates from the Department of National Defence until they are independently validated," the public works minister told the House of Commons.

"The secretariat needs more time to do that. We respect that. They will take as much time as they need to get it right."

Defence isolated from process

Even though Ambrose wouldn't commit to a timeline, indications were it will likely be the fall when a full analysis of Canada's participation in the troubled program is expected to be final. Her office confirmed that in a news release Wednesday.

The National Fighter Procurement Secretariat, which the government set up in the wake of Ferguson's report, is now up and running, Ambrose's office announced Wednesday. Former auditor general Dénis Desautels is on the committee, which is otherwise made up mostly of public servants. McMaster University professor of economics Ken Norrie is also on the secretariat.

The secretariat of public servants has taken over control of the fighter jet procurement process from National Defence.

The extent to which Defence is isolated was evident when MacKay was later asked about the outside expert that will measure the program.

"Yeah, I'm not sure. That's something you'd have to ask Minister Ambrose," he said.

Interim Liberal Leader Bob Rae jumped on the comments, saying it was an illustration of how the government didn't trust MacKay, or his department, to get it right.

Officials got new cost figures in May

Arguments over the cost of the radar-evading jet have been at the centre of a political storm for the last 18 months as both the air force and the Harper government insisted they would pay $75 million for each aircraft, despite of mounting evidence in the U.S. that it would be higher.

The Tories drew up a seven-point plan to answer the auditor's criticisms and promised the F-35 procurement would start from scratch with independently verified estimates and assumptions.

Defence planners get their data and costing estimates from the Pentagon's joint strike fighter office, which oversees the entire program for the U.S. and its allies.

New Democrat procurement critic Matthew Kellway said adding up the number shouldn't be a complicated exercise given that since 2006 the federal government has received 15 formal briefings from the U.S. Defence Department and Canadian officers work at the program office in Washington.

"This should be easy," he said. "The Americans post their costing information on line, but we will accept a hard copy."

New costing figures, which take into account delays and declining orders, were provided to Canadian defence officials last month, but the government wants to see a review of the entire program before proceeding.

The price tag of the F-35 is expected to vary year to year, depending the number of orders received by the manufacturer, Lockheed Martin. MacKay and Associate Defence Minister Julian Fantino have said Canada intends to order most of its 65 jets at peak production time, when the cost per aircraft is the lowest.

But development delays and other setbacks have pushed that high cycle off until at least 2020, the time when the Canadian air force's current fleet of CF-18 jet fighters is to begin retiring.

with files from CBC News