Residents in Dún Laoghaire, South Dublin have questioned the council's decision to provide a "letter of comfort" to the developer of a local golf course.
The letter consents to the inclusion of council lands in the developer's planning application.
The residents have also called for the preparation of a local area plan before the council gives approval to the controversial development.
Cosgrave Developments has applied to Dún Laoghaire-Rathdown County Council to develop 856 homes on Dún Laoghaire golf course, including 230 houses and 626 apartments in four blocks.
The planning application is confined to the southern part of the land - 47 acres on the south side of the Upper Glenageary Road, which bisects the course.
A 5.5-acre public park is included as well as a commercial centre with a convenience store, café, shops and office space.
The "letter of comfort", obtained by local group the Combined Residents to Save Open Space, was provided by the council to RPS Planning and Environment, consultants for Cosgrave Developments.
It states that "Dún Laoghaire Rathdown County Council consents to the inclusion of lands in its ownership as part of the planning application for the above project" and is signed by a council official. The specific land that the letter refers to has not been clarified, but it is thought to refer to green spaces near the boundary with the golf course.
Gene Feighery, spokeswoman for the combined residents' group, asked how the council could give over residential amenities and public open spaces to facilitate a developer.
"Every resident who lives adjacent to county council lands can no longer take comfort that it is safe," she said. "Does this mean that the open space on the golf club lands, in a few years time can be signed away and encroached upon to facilitate a developer?"
She backed calls for the preparation of a local area plan.
The residents' group will be hosting a meeting on Tuesday to discuss the application.
A council spokesman said it was unable to comment on pending planning applications but said the planning process was the most transparent in Europe and was based on legislation and the county's development plan.
TD Ciarán Cuffe (Green Party) said it would have been better to have brought the matter before councillors before including council land in a "letter of comfort".
