An MSP has demanded a breakdown of the £9 million spending on air traffic control centralisation.
Isles member Beatrice Wishart has made the call after the tendering process for the controversial air traffic management strategy was cancelled.
She has written a letter to transport minister Graeme Dey.
In her letter, Ms Wishart welcomes the procurement cancellation and reiterates her misgivings about safety, connectivity and job losses of the proposed project.
The cancellation by Hial of the tendering process follows an agreement reached in October between management and the Prospect union.
Prospect national secretary Richard Hardy said: “Prospect welcomes the written answer by transport minister Graeme Dey indicating that Highlands and Islands Airports Limited (Hial) has cancelled it’s tender process in respect of the remote towers project.
“Prospect and Hial are engaged in sensitive negotiations in relation to the future delivery of air traffic services, but our long term goal has always been to maintain high quality, high value air traffic jobs in their current location.”
Hial said it had contacted the companies involved in the remote tower procurement in October to confirm that the tender exercise had been halted.
It said would be inappropriate and unfair to expect tenderers to remain engaged in the procurement process given that the timescale, scope and extent of possible future remote air traffic provision had yet to be agreed by all key stakeholders.