Wigan Council has heard the government inspector's suggested modifications to its Core Strategy development proposal.
Taking a 15-year plan period of 2011-2026 into account, the inspector last year considered that there should be provision for at least 16,500 dwellings.
In inspector Kevin Ward's view, there was a shortfall of at least 2,500 dwellings in terms of realistically deliverable supply within that period.
The inspector reported that there was a specific need to demonstrate a deliverable five-year supply of at least 6,300 dwellings from the likely adoption of the plan.
The letter stated: "There is a significant reliance on sites without planning permission to achieve a five-year supply overall.
"I consider that the council's proposals to address my earlier concerns would not provide a policy framework which allows for a realistic five-year supply of deliverable sites to be identified.
"In this respect, the council's proposals would not result in a plan that is positively prepared, effective and consistent with national policy."
In May 2012, the inspector decided to suspend the examination for six months to allow the council to carry out additional work and public consultation.
Last week the second plan Wigan Council had submitted to the secretary of state was opposed under the belief that it would not provide for an adequate supply of housing land.
Inspector Ward outlined a number of suggested changes in his latest letter, including halving the number of new homes planned for Lowton and Golborne.
The inspector recommends Wigan Council limit the number of houses to be built in Lowton from almost 2,500 to around 600.
Inspector Ward's latest letter stated: "I have some doubts over the assumed combined annual rates of delivery at Northleigh, South of Hindley and East and South of Atherton at times during the plan period.
"Given that the council is yet to determine the application for outline planning permission at Stone Cross Lane, the delivery of houses in 2013/14 appears unduly optimistic.
"Likewise, I am concerned over the realism of expecting 50 houses to be delivered at Garrett Hall in 2014/15 given that a planning application has not yet been submitted."
The council now has until Friday 22 March to confirm whether or not it still wishes the inspector to recommend modifications.
If it does, the inspector will liaise with the council via the programme officer in order to prepare the detailed wording of modifications for consultation.
No one at Wigan Council was available for comment.