The evidence is required as part of the examination process of Shropshire Council's local plan – a document which sets out sites in nearly every town and village in the county where a combined 30,800 homes would be built up to 2038.
Hearings on the plan took place in July, but at their conclusion the planning inspectors conducting the process asked Shropshire Council for more information to back up their position on controversial 'duty to co-operate' rules.
The duty to co-operate is a requirement for neighbouring councils to help provide space for housing and business land, where other authorities are unable to do so.
Shropshire Council's local plan includes 1,500 homes under the duty to co-operate rules. They will contribute to a shortfall of housing experienced by West Midlands councils.
However, the Association of Black Country Authorities (ABCA) – made up of Dudley, Walsall, Wolverhampton, and Sandwell councils – is pushing for Shropshire to take on more of their development responsibilities – as many as 3,000 more houses.
That call is backed up by solicitors representing the Bradford Estates, which wants to build up to 3,000 homes, and a large business development, on green belt land west of Tong and north of Junction 3 of the M54.
Shropshire Council argued at hearings that it had fulfilled its duty to co-operate, however, examining planning inspectors Louise Crosby and Carole Dillon asked for specific answers over the process by which the authority decided on the level of help it would provide West Midlands authorities.
They gave the council until August 5 to respond.
In response Shropshire Council has said it will reply by September 12 – more than a month later - but the situation has been accepted by the inspectors.
In a letter to the inspectors, the council's planning policy and strategy manager Eddie West said that the number of staff on holiday had made it difficult to respond by the deadline.
He said: "The council can confirm this request is being undertaken as a priority, and acknowledge you will not be in a position to advise on how the examination will proceed until you have received this additional information.
"Whilst this information is currently being compiled, due to significant number of annual leave commitments during August, the council are aiming to respond fully to this request in the week commencing September 12.
"We will of course seek to get this information to you earlier if possible."
The inspectors have replied saying they look forward to receiving the response.
The outcome of the issue will have major implications in deciding whether the Bradford Estates plan can go ahead.
Currently the proposal is not included in the local plan but if the inspectors find Shropshire Council has not fulfilled its duty to co-operate, it could provide fresh hope for the scheme.