Highlands and Islands MSP Jamie Halcro Johnston has raised fresh concerns over air traffic control centralisation.
In a letter to Transport Secretary Michael Matheson, the Conservative MSP said Hial progressing with plans to introduce remote control before an island impact assessment is completed was not consistent with the spirit of legislation.
He said: “It’s no secret that there are profound concerns across my region – particularly in Orkney, Shetland and the Western Isles – about the safety implications of relying on unmanned control towers.
“The Scottish government own Hial – they promised that an islands impact assessment would take place and it seems clear that any changes should not happen until the assessment has been carried out.
“I very much hope that, even at this late stage, the Scottish government will relent and start listening to the concerns of our local communities; those which will be most impacted by these proposed changes”.