BRITISH Airways has appealed for compensation from the European Union and the UK government over the chaos caused by the volcanic ash cloud which has grounded flights.
The company estimates that the crisis is costing it about £15m to £20m a day.
Chief executive Willie Walsh called on the government to adopt new policies that would "allow us to resume flying".
BA has carried out a test flight which did not report any difficulties.
Scottish airspace is expected to opened up at 7am on Tuesday, while the rest of the UK remains under review.
Meanwhile travel firm TUI Travel has said that the disruption has lost the group about £20m so far.
Europe’s largest travel group, said it was losing between £5m to £6m a day during the crisis.
It also confirmed it has 100,000 holidaymakers stranded abroad.
TUI chief executive Peter Long said: "It's a big cost the sooner we can back to normal the better.
"We went into crisis mode last Thursday, it's a shame it has taken until Sunday (for the Government to act)."
He said the company is considering sending its own two cruise ships to pick-up stranded holiday makers.
Meanwhile airlines and safety offices are due to hold a crisis summit on when flights can start operating from the UK again.