Air New Zealand says it will not resume flights to Europe until at least Tuesday morning, as ash from a volcano in Iceland continues to disrupt flights.
The latest message to passengers on the airline's website says airspace restrictions across Britain will remain until at least 6am on Tuesday.
The two Air New Zealand flights to Europe due to depart on Monday evening will terminate in Los Angeles and Hong Kong respectively.
The website says NZ1 from London to Los Angeles and Auckland, due to depart Monday afternoon British time remains on schedule, but is dependent on the airspace restrictions being lifted.
Passengers may defer their travel to another Air New Zealand flight without penalty and those who no longer wish to travel can apply for a full refund, the airline says.
PM's plans in question
The grounding of flights could affect Prime Minister John Key's travel plans this week.
Mr Key is due to travel to Gallipoli for ANZAC Day commemorations, and is scheduled to leave on Wednesday on a commercial flight.
He says he has been advised that he will be able to get there, and he hopes that will be the case. But he says he is not completely confident.
He says the flight restrictions in Europe will have an impact on New Zealand businesses, including the export and tourism sectors, though he has had no official advice on the potential costs.
Weekend disruption
Some Air New Zealand passengers bound for Europe were told at the weekend they would be unable to fly for at least two and a half weeks.
On Sunday night, 150 passengers cancelled their place on Air New Zealand flight NZ2 to London via Los Angeles.
A visitor from Northern Ireland, James Bradley, says he's been told that if he waits in New Zealand he won't get a flight until 6 May. He says if he opts to fly to Los Angeles, there's no certainty about when he will get a forward flight.
New Zealand-based Briton Giles Ingham, who is trying to get to Britain for a wedding, planned to fly to San Francisco and get on the earliest onward flight possible.
Financial impact
Meanwhile, Air New Zealand spokesman Mark Street says the financial impact on the airline will be relatively small because it operates just 12 flights a week to London via Los Angeles and Hong Kong, compared to 145 flights a week to Australia.
Aviation analyst Peter Clark estimates it is costing the company $70,000 a day to accommodate 700 stranded passengers in Los Angeles and Hong Kong.
"So Air New Zealand will have to make a decision shortly. It's quite good that Air New Zealand has paid for them - they don't have to."
Worldwide, airlines are estimated to be losing some $US200 million a day.
The head of private reseach at Craigs Investment Partners, Mark Lister, says the problem will cost the airline, and any other company operating in this sector, in the short term, but it's not yet clear how much, or who will pay.
Shares in Air New Zealand fell 4 cents (2.8%) on Monday morning, to stand at $1.37 at midday.
