As airlines start counting the cost of covering stranded passengers' hotel fees, pressure is rising on governments to reassess the rules on what travellers are entitled to.
The Board of Airline representatives in the UK, representing more than 90 airlines, has called on the UK government to tackle the European Commission (EC) over what it calls "unfair" regulations.
Mike Carrivick, chief executive, said "The eagerness of the EU and the UK government to publicly state that airlines have a responsibility under EU Regulation EU261/2004, to accommodate and feed passengers booked on flights cancelled by the volcanic disruptions, is a misuse of the regulation."
He said the regulation was intended intended to apply when airlines had individual delays or cancelled flights.
"It was never intended to apply to wholesale shutdown of the airways system imposed by governmental rulings and without any limitation of time... This Regulation, when used in this way, is draconian, disproportionate and often impractical," said Carrivick.
Three European airline associations are also calling for change.
The ELFAA (European Low Fares Airline Association), ERA (European Regions Airlines Association) and IACA(International Air Carrier Association) want a "firm commitment" from the EC and member states to support airlines affected by the crisis.
A joint statement said: "European governments cannot ignore the massive economic consequences of their decisions on airlines.
"Airlines note that Regulation 261/2004 is the only European regulation that imposes unlimited obligations regarding consumer rights on commercial companies for events that are totally outside their control.
"When legislation concerning passengers' rights was drafted, legislators chose to ignore the industry's warnings that it was an inappropriate response to the type of Europe-wide crisis that airlines now face: its application now is transforming a crisis into an economic catastrophe."
The associations added that the prolongation of this situation threatens their business viability with serious risks to both routes and jobs.
Ryanair's CEO Michael O'Leary called the EU261 regulation "absurd and discriminatory" and said the airline will work through the ELFAA to "persuade the European Commission and the European Parliament to alter this regulation to put this reasonable limit on these reimbursement claims".
O'Leary said: "While competitor ferry, coach and train operators are obliged to reimburse passengers reasonable expenses, this reimbursement is limited to the ticket price paid to those operators. Yet the airlines are required by regulation to meet potentially unlimited expenses, in circumstances where there has been a catastrophic closure of European airspace over the past seven days."
www.bar-uk.org www.elfaa.com www.eraa.org www.iaca.be