The response showed that between August 2020 and March 2023, the Scottish Government, which wholly owns the airport’s holding company, spent £2,519,779.61 on “Professional fees in relation to the sale of Prestwick Airport”.
Around £115,000 went on “legal advice” but the bulk was on reimbursing the airport for unidentified “professional fees”.
SNP ministers bought Glasgow Prestwick for £1 from New Zealand firm Infratil in 2013 to ensure its survival and have since loaned it more than £43million.
Ryanair is now the only major passenger airline to use the Ayrshire site for regular flights.
However, after habitually running a loss, the airport has returned to profit in recent years thanks to cargo services and refuelling US Air Force planes.
In 2019, ministers tried to sell off the airport and in May 2020 announced a preferred bidder had been found.
However the firm later pulled out over Covid’s devastating impact on the airline industry.
Ministers then tried to sell it a second time and a new preferred bidder was identified in February 2021 only for that sale to fall through as well in December 2021.
Ministers said they had “decided not to proceed with a sale at this time”.
The Government still says the airport is still technically for sale, but there has been no public confirmation of another bid since the possible 2021 sale was axed.
LibDem MSP Willie Rennie said: “Lawyers and fixers are getting rich touting around the sale of Prestwick but it seems like it is all to little avail.
“This is the type of poor economic mismanagement that has come to characterise SNP ministers.
“The Scottish Government needs a plan for Prestwick that recognises the importance of meeting our climate change commitments and getting a good deal for taxpayers.”
The Scottish Government said it was committed to “returning it to the private sector”.
A spokeswoman said: “The airport is currently profitable, and the Government receives expressions of interest periodically regarding its purchase.
“Ministers must be confident any sale would not only represent value for the taxpayer but would put the business on a firm footing.”
Because of its windy coastal location, Prestwick is the only UK airport unaffected by fog.
It has two runways and a terminal building originally constructed for four million passengers a year, with capacity for 18 check in desks, 10 gates and 12 stands.
Around two-thirds of the 356 hectare site is used for aviation activities.