More than 500 people have signed a petition calling for Northern Ireland Water to rethink plans to sell off a popular North Down woodland.
Alliance councillor Andrew Muir, who launched the online petition to save Cairn Wood, said he believed NI Water may not even have the right to proceed with the sale.
He said a previous Freedom of Information request had revealed that a 150-year lease was signed by previous owners Bangor Borough Council in 1964 and the plan to sell the forest must be halted without delay.
Councillor Muir said: "It is essential that Cairn Wood is removed from the sale and left within public hands, open for public use on the same basis as enjoyed by many over previous decades."
NI Water said it had an obligation to dispose of assets that were no longer of use, but no expressions of interest were received from the public sector in respect of Ballysallagh Upper impounding reservoir and its surrounding catchment.
"For sites where no expression of interest has been received from the public sector, NI Water will advertise the property for sale on the open market."