The chief operating officer of Gatwick Airport has said it would remain closed on Thursday evening and potentially all of Friday after drone activity was spotted in the last hour.
Chris Woodroofe said 120,000 passengers' flights had been disrupted and that the drone that has plagued the airport since Wednesday evening is still in the air.
He told Sky News: "My apologies to all those passengers who have seen this disruption from the criminal activity from these people who are purposely disrupting our airport and their travel so close to Christmas."
Mr Woodroofe added: "We have had the police, we have had the military seeking to bring this drone for the last 24 hours and to date that has not been successful, so Gatwick airport is still closed.
"It is closed for the rest of this evening and our intention is to review on an ongoing basis whether we can reopen tomorrow.
"But we are working up contingency plans all the way through to no flights tomorrow."
The incident led to calls for more action to tackle illegal drone use.
The runway has been closed almost constantly since two drones were spotted being flown inside Gatwick's perimeter at 9pm on Wednesday.
It was reopened at 3am on Thursday but was closed 45 minutes later after the drones re-emerged.
Police described the devices as "industrial" models and are treating the incident as "a deliberate act to disrupt the airport".
Transport Secretary Chris Grayling said there was no known motive for the pilot of the "commercial" drone.
Night-flight restrictions will be lifted at other airports – probably those which serve London – so that "more planes can get in to and out of the country".
"Apologies for the residents affected, but it's right and proper that we try and sort people's Christmases out," Mr Grayling said.
Passengers faced severe disruption as flights were unable to leave the tarmac at Gatwick, while many inbound flights were diverted to alternative airports as far away as Amsterdam and Paris.