Flights from UK airports have been suspended since Thursday
British pilots have called for a banking-style rescue of the UK airline industry, which has been ground to a halt by a volcanic ash cloud.
The British Airline Pilots' Association (Balpa) said the financial impact "could not be more serious".
"The government needs to step in and show the same approach it took to keeping banks afloat," Balpa said.
"If it fails to act it will find that an equally-important foundation of our economy is lost."
The airline industry is still struggling to recover from a global slump in demand for air travel, brought on by the economic crisis.
It is estimated that the flight restrictions that have been in place since Thursday will cost airlines about $200m (£130m) a day.
Balpa also called on action from the Europe Union.
"The EU needs to act as their delayed passenger compensation scheme was never designed with this situation in mind and is now crippling our industry," the union said.