Volcanic Ash Disrupts Flights
The cloud of volcanic ash spreading from the Grimsvotn volcano in Iceland has already lead to some airlines cancelling flights in the UK, with Scottish services the most affected.
But Transport Secretary Philip Hammond told the BBC any disruption would be unlikely to last long.
He said that following last year's ash cloud, "we learned a great deal", and the government had worked with airlines and engine manufacturers to maintain safety with far fewer interruptions to services.
Thousands of passengers have had their flights cancelled because of drifting ash from the Icelandic volcano.
Airports affected include Londonderry, Glasgow, Edinburgh, Prestwick, Durham Tees Valley, Newcastle and Carlisle.
European air traffic controllers said 252 flights had been cancelled so far.
However Ryanair said it had made a test flight over Scotland and challenged a ruling some flights should be grounded.
The Irish carrier said its 90-minute flight at 41,000ft showed there was "no visible volcanic ash cloud or evidence of ash on the airframe, wings or engines".
A decision on whether permission is given to fly rests with each airline's national aviation authority.
Ryanair, which is continuing to check in passengers at Edinburgh, has submitted a safety case to the Irish Aviation Authority (IAA) to fly from Scotland.
Ryanair said the "red zone" over Scottish airspace where ash has been classified "high-density" was invented by the Met Office and the Civil Aviation Authority But a CAA spokesperson said: "The CAA can confirm that at no time did a Ryanair flight enter the notified area of high contamination ash over Scotland.
“Just what we could do without when people are going on their holidays next week, lets hope these disruptions are soon sorted out” says Greengates Builders Merchants Accrington, Lancashire.