Manchester City Council wants city centre residential developers to explain, in detail, why they cannot provide affordable housing.

This will involve revealing exactly how landowners got their hands on sites and what they paid their agents or intermediaries. The information will be made public.

The changes arise from a consultation on the paperwork required to validate a planning application, open until 14 September. The document requires a full viability assessment where the affordable housing provision, or a financial contribution in lieu, is not being proposed.

The document states: "Information should be provided in its entirety. Applicants should also be aware that the assessments will be made publically available in the same manner as other documents that form part of the planning submission."

Applications must show existing use value plus a premium supported by an independent valuation, land acquisition price and the basis of its purchase (for example whether it is subject to planning), the purchase process and purchase costs including legal fees and agent fees, professional fees, contract-related fees and something defined as "abnormals".

The document will also have to show construction costs, the cost of financing and estimated returns.

The city council also adds: "Where a proposal involves the loss of employment land, there will be a requirement to provide information about the impact on jobs."