The Harper government is defending its decision to purchase a new generation of fighter jets without a single competing bid.

The government is spending nine billion dollars to buy 65 of Lockheed Martin's F-35 Joint Strike Fighters.

Costs could rise to $16 billion with maintenance costs, but Public Works Minister Rona Ambrose told reporters in Ottawa Friday she could not put a figure on those costs.

Defence Minister Peter MacKay says the planes are urgently needed to ensure Canada's fighter-aircraft fleet remains the best in the world.

But an analyst at a defence think-tank says with the sorry shape of the economy, now is the wrong time to buy new jets.

Steven Staples of the Rideau Institute calls the planes ``flying Cadillacs'' that are both unaffordable and unnecessary.

Liberal Leader Michael Ignatieff says he'd put the deal on hold if he were elected prime minister. Ignatieff also criticizes the government's decision to proceed with the non-competitive contract.

But MacKay says there was competition when the previous Liberal government signed a memorandum of understanding with Lockheed to develop the jets.

He says that government invested a lot of public money, and he can't understand what he calls Liberal hypocrisy that "seems to soar higher than this aircraft."

Watch F-35 Joint Strike Fighter short take-off and landing (flash required).