Air Southwest flights are cancelled
A union says it will fight moves to dock the pay of Devon teachers stranded abroad after flight cancellations.
Many northern European flights have been cancelled because of dust in the atmosphere from a volcano in Iceland.
Devon County Council warned pay could be docked, although it was reviewing the policy "in light of the extreme circumstances".
Teachers' union the NASUWT said members were worried about the "completely unacceptable" policy.
Fiona Westwood, South West organiser for the NSAUWT, told BBC News: "It is completely unfair that teachers are penalised.
"Teachers have no choice about when they take their holidays and have no control over global events that mean they cannot get back to work."
A Devon County Council spokesperson said: "Our policy states that in situations where staff are unable to work because of events such as severe weather, and they are unable to take flexi time, annual leave, time off in lieu or work extra hours, they will be expected to take unpaid leave.
"However in light of the extreme circumstances caused by the volcanic ash, we are currently reviewing the application of this policy and will provide staff with further guidance as soon as possible."
Paddy Marsh, head teacher of Widey Court School in Plymouth, is stranded in Australia after visiting his daughter and grandchildren.
He said: "Every time you think the airspace is going to open you get the message that the volcano has gone up again and you just have to sit still."
Widey Court also has a teacher stranded in Jamaica.
Mr Marsh said: "I know of quite a few other head teachers and teachers who are abroad, but there is nothing you can do about it.
"There hasn't been anything like it since World War II."
Tim Jones from the Devon and Cornwall Business Council said the crisis had already cost the local economy £15m and the bill was rising.
"Disruption to businesses is enormous," he said.
All Flybe and Air Southwest planes at Exeter and Plymouth have been cancelled.
Experts fear rock, glass and sand particles from the volcanic ash from Iceland could jam aircraft engines.