Residents have opposed a plan submitted by Queen Elizabeth's estate to convert disused stables into a house within the boundary of a Doncaster castle.
The Duchy of Lancaster, which manages the Sovereign's land, estates and assets, wants to renovate and alter the use of a cottage within the grounds of Tickhill Castle.
The plan has been looked over by council planning officers and is recommended for approval, despite dozens of objections from Tickhill residents.
This proposal involves the renovation and extension of Castle Cottage and the conversion and extension of the redundant stables into a single house.
A previous plan to build a double garage on the side of the home has been scrapped after consultation.
Castle Cottage is said to be an unlisted two storey farmhouse with attached single storey stables and outbuildings at the foot of Tickhill Castle.
The building is located along the line of the historic ditch surrounding the motte.
In a letter to Doncaster Council's planning department, Tickhill resident Graham Smith said: "If the castle was in any city in the south, this would never happen. The castle andits environment must be preserved for future generations."
Patrick Doran, who lives close to the castle, also formally objected.
He said: "The proposed building is on land which houses an ancient monument of significant local and national interest. We feel it is highly inappropriate to even consider developing new build properties in and around the area that houses the castle monument
"The proposed development is in the heart of an existing green belt area and therefore wholly inappropriate for the development of new buildings.
"We protest most strongly against this proposed development for the above reasons."
Historic England support the application on 'heritage grounds' and 'remains supportive' of the application to bring the farmhouse back into use.
Principal planning officer Gareth Stent from Doncaster Council, said: "The proposed alteration to Castle Cottage and the conversion of the stables will bring a redundant building back to life and cause no significant harm to the living conditions of surrounding occupiers, no significant harm to the character and openness of the Green Belt and no significant harm to the heritage asset.
"The scheme raises no concerns form consultees, is policy compliant and is supported."