OTTAWA -- The Harper government is trimming its expected order of Arctic patrol ships and evaluating a set of unsolicited proposals to convert civilian cargo ships for use by the Canadian navy.

So say several government, defence and industry sources who spoke to The Canadian Press on condition of anonymity.

Both steps are a sign that more modest expectations have been set for the government's national shipbuilding strategy, which after three years has yet to deliver any new vessels.

Sources familiar with the plan, but not authorized to discuss it publicly, say National Defence and Public Works are studying a proposal from the Davie Shipyard in Quebec for a five-year lease of bulked-up civilian cargo ships.

At the same time, negotiations with Halifax-based Irving Shipbuilding for the construction of Arctic offshore patrol ships have seen the government scale back a plan to buy as many as eight vessels to enforce sovereignty in the North.

The government now plans to buy just five light icebreakers, with an option for a sixth.