“The development, whilst being identified as having less than substantial harm would result in the loss of an area of countryside adjacent to the building which contributed to its significance as a principal house to a large country estate and is in itself identified as a non-heritage asset.”

The council received objections to the scheme from Blackthorns Community Association, Campaign to Protect Rural England and the Haywards Heath Society.

More than 350 letters of objection have been written to the council by residents concerned about the impact on listed buildings, the loss of valuable recreational space, increased traffic in the area and the increase in flood risk. Others have argued the area does not need more housing for commuters.

An independent consultant’s report has been submitted on behalf of Save Birchen Fields Action Group – which argues the proposal is ‘unsatisfactory’ and will impact Medieval assart fields, a historical sunken lane and an important hedgerow.

Developers Crest Nicholson submitted the plans in December 2014 – 11 months after the developers’ first bid for new homes on the land. If it goes ahead, there will be 14 affordable homes – which will not be ‘distinguished’ from the other houses.

The planning statement describes the site which ‘comprises countryside land’ as a ‘sensible, logical and sustainable’ location for the extension of a town. Developers say they have considered the ‘impact of additional traffic movements’ into and out of the site.