Alan Denney, national secretary of Prospect Scotland, said that HIAL had given assurances as recently as Tuesday 11 June that its air traffic provision would remain in the public sector. But on 12 June it had admitted that a review of the service would include its possible contracting-out to a private sector provider. Meetings have been scheduled for 17 and 24 June with SERCO and National Air Traffic Services.

"As a wholly-owned Scottish Executive company, HIAL comes under the Scottish Parliament’s jurisdiction," said Denney. "Privatisation of this vital public service must be debated in Holyrood before any decision is taken."

Prospect represents air traffic controllers throughout the UK, including 32 controllers at HIAL, and has fought a longstanding campaign to keep ATC provision in the public sector.