Thousands of Britons have headed back to the UK as airlines ran near-normal services again following the ash cloud crisis.
Around 2,200 of the hitherto-stranded tourists were sailing back from Bilbao on a new £500 million luxury cruise ship sent out on a rescue mission.
As travellers returned, budget airline Ryanair performed a U-turn on reimbursing passengers.
On Wednesday, the Irish no-frills carrier's chief executive Michael O'Leary said he would reimburse travellers only the original price of their air fare and no more.
But the airline said it would comply with the regulations under which EU airlines are required to reimburse the "reasonable receipted expenses of disrupted passengers".
Both Mr O'Leary and Ryanair stressed that this was not compensation, merely reimbursement. Mr O'Leary said that if claims were not reasonable, they would not be met.
Transport Secretary Lord Adonis welcomed what he described as Ryanair's "revised statement", saying the Government and the Civil Aviation Authority had told Ryanair "in the strongest terms" that they were expected to comply with the EU regulations.
Liberal Democrat transport spokesman Norman Baker had been critical of Mr O'Leary's initial defiance of the regulations.
Later, shadow transport secretary Theresa Villiers said a Conservative government "would conduct a wholesale review of the rules governing compensation and travel insurance arrangements for air passengers".