Postponing the decision on whether to further upgrade Canada's aging fleet of Aurora patrol aircraft raises questions about the country's ability to defend its Arctic sovereignty, an advocacy group says.

Prime Minister Stephen Harper has said protecting Canada's Arctic sovereignty is one of his government's top priorities. He pledged to defend the Arctic during the federal election campaign, promising to spend billions on underwater sensors and three new naval ice-breakers, among other things.

But defence sources told the Canadian Press that the National Defence department last week delayed making a decision until Dec. 18, almost one month past the government's own deadline and at least four days past Parliament's scheduled Christmas break. Some, including New Democrat MP Peter Stoffer, interpret the delay as a sign the government may be preparing to scrap further upgrades.

The government has already spent more than $900 million upgrading the CP-140 Auroras' radar and navigation systems, and defence contractors were preparing for the next round when plans were put on hold.

"It would seem that the government, having made those pronouncements, is not necessarily following through on the capability needed to maintain that sovereignty — at least from the perspective of an air response and control capability," said retired Col. John Orr, who speaks for the advocacy group, Friends of Maritime Aviation.

The fleet of 18 Auroras, of which 14 are based at CFB Greenwood in Nova Scotia, are capable of flying 9,000 kilometres without refueling and are used to patrol the coastlines and the North.

More than $900 million has already been spent upgrading radar and navigation systems for Canada's aging Aurora patrol aircraft.
(CBC)

Earlier this month, the Canadian air force cancelled Aurora surveillance flights in the North for the next several months. Defence experts speculated the move was the result of Canada's combat efforts in Afghanistan, which is taking huge amounts of money and squeezing missions at home.

A spokesman for Defence Minister Peter MacKay said in an email message, "The minister has not made a decision on this file and is expected to within coming weeks.

"The reason for the postponement is that the minister wants all the information possible on this important file before he does decide the way forward, and he's waiting for more advice," Dan Dugas said.

In 2005, IMP Aerospace and L-3 Electronic Systems were awarded two contracts totalling $961.1 million to upgrade the Auroras.

Industry officials have told MacKay it would be cheaper to continue with the upgrade and keep the planes flying until 2025, rather than spend several billion dollars to purchase new ones.

But the air force has countered that the slow pace of the refurbishment means it could have new aircraft by the time the old ones are back in service, CP reported, citing a defence expert.

Bailing out on the rest of the contract would result in a "managable" penalty, the source admitted.

The air force is said to be looking at two aircrafts, the P-8A Poseidon and the ASTOR.

With files from the Canadian Press