Haddington Sheriff Court is set to be put up for sale on the open market and could become housing, despite fierce opposition to its closure.
The court, which dates to the mid-19th century, serves a population of approximately 100,000 and all business will be moved to Edinburgh when it shuts in January 2015.
Former Labour leader and East Lothian MSP Iain Gray, who has fought the plans, said the Scottish Court Service (SCS) had discussed selling the building to housing developers.
Mr Gray said: “The court service talked about housing as a possible use for the building, but that seems highly unlikely to me.
“We should certainly oppose anything which would change the character of the building, given its situation at the heart of the town.”
He also urged a rethink over the closure plans – a move which will see ten sheriff courts across Scotland shut down.
Campaigners last year said it would cost more than £500,000 to transfer cases to Edinburgh, something denied at the time by the SCS.
Mr Gray said: “Frankly, given recent figures showing that Edinburgh cannot cope as it is, the best thing the SCS could do is admit their mistake, change their mind and keep Haddington for what it is good for – a court.”
Any move to transform the building into housing would upset residents in the East Lothian town, according to the chairwoman of Haddington community council, Jan Wilson.
She said: “It’s a really beautiful building and you would not want anything done to spoil it. Honestly, I would hate it to become housing.”
Closure of the court would also create uncertainty over the future of marriage and citizenship services based there, campaigners have said.
According to the court’s consultation document, published by East Lothian Council in December 2012: “The council has been taking steps to reduce the size of its own estate in recent years, and so it cannot be assumed that the council would be a willing buyer.
“Should the SCS sell or lease for an alternative use, the council would be directly affected by sharing space with the new owner/tenant.
“The council would have the right to object to change of use during the planning process.
“The council’s Adam Room, which hosts marriage and citizenship ceremonies, shares the entranceway with the court.
“If the court building were to be closed up or sold, the council might have to consider relocating these ceremonies, with consequent costs.”
No-one at the SCS was available for comment.