The federal government says it doesn’t know when Quebec shipyard Chantier Davie will deliver a fleet of new icebreakers to the Canadian Coast Guard.

Officials say the schedule will depend on negotiations with the shipyard, which was formally added to Ottawa’s multibillion-dollar shipbuilding strategy last week.

There are long-standing concerns about the Coast Guard’s existing icebreakers and whether replacements will arrive in time.

Auditor General Karen Hogan noted in a report last year that the fleet is already on average more than 40 years old, increasingly prone to breakdowns and expensive to maintain.

Hogan concluded there was little room for delays if Ottawa wants to maintain its current icebreaking capabilities, which are critical for keeping Canada’s waterways open to trade and resupplying northern communities.

University of Calgary professor Rob Huebert says the government’s decision to buy three second-hand icebreakers from Davie will help in the interim, but building new icebreakers is time consuming even without the added complication of negotiations.