Councillor Gerald Vernon-Jackson said negotiations were ongoing around how much affordable housing it would include and said the majority of concerns that prompted councillors to defer a decision in January were still unresolved.
'Some amendments have been made but they've not changed a lot,' he said. 'Two of the main concerns were around the loss of protected trees and the three homes proposed in the woodland area.
'They have tried to change things to keep some of the most important of those trees but those homes are the most profitable in the development and are still in the proposal.'
The £55m PJ Livesey development includes the construction of more than 200 homes after the site was sold by the NHS due to much of it being vacant and because it was 'not suitable for the delivery of modern mental health services'.
Council planning officers put the scheme to the planning committee in January with a recommendation that it be approved, however councillors deferred a decision over the lack of up-to-date traffic data and the age of the viability assessment used to justify the lack of any affordable housing.
Cllr Vernon-Jackson said discussions had been held between the developer and the NHS around including a contribution but said he did not expect this to improve matters.
'I think it's entirely possible there will not be much, if anything at all,' he added. 'The council's offer for the site would have delivered 50 affordable homes and saved the NHS a significant sum of money with it spending £1.6m a year on it.
'We're looking at several months before a decision is made.'
In January, a campaign was launched by Milton residents who opposed the housing plans, with roughly 300 objections submitted to the city council – including a representation from Cllr Vernon-Jackson himself.