The Civil Aviation Authority still has almost 65,000 passengers caught up in the Monarch failure to return to the UK on special repatriation flights.

The emergency flying programme completed 57 flights on its fourth day of operation yesterday, returning 10,604 people to the UK.

The regulator plans to operate 56 flights today to bring more than 11,100 people back to the UK.

Around 64,788 passengers are still to be flown back to the UK out of the 110,000 who were abroad with 10 days of the replacement flying schedule remaining following Monarch’s collapse in the early hours of Monday.

CAA group director of consumers and markets, Richard Moriarty, said: “We are working around the clock to bring home 110,000 people from around the Mediterranean and beyond.

“Our programme remains on track. Last night by the end of day four of the 14-day programme we had a total of 45,000 people back in the UK. Today, our aim is that a further 10,000 people are home.

“This will mean half of the people abroad when Monarch collapsed on Monday morning will be back in the UK by the weekend.

“So far we’ve managed to bring the vast majority of people back to the UK on the day they were due to fly back with Monarch.”

He added: “We are not complacent and we still have a long way to go.

“Just like for normal commercial airlines, our schedule will be subject to delays caused by weather events, technical faults and external events beyond our control.

“Our website has proved invaluable in getting information on replacement flights to people and has now had over one million unique visitors.”

Thomas Cook said yesterday that it was working with the CAA on the plan to repatriate all Monarch customers in resort including those on Thomas Cook holidays.

“We are also providing Monarch Holidays and flight only customers with support in destination,” the operator said.

The travel group added that it was trying to find the best alternative to avoid disruption to the plans of people due to travel on a Thomas Cook holiday in the coming weeks on a Monarch Airlines flight.

But the company warned: “Unfortunately demand for flights is so high that there are very limited alternatives available and in some cases we may have no choice but to cancel your holiday and provide a full refund of the cost.

“If your Thomas Cook holiday has to be cancelled or amended because no alternative flight is available, we will offer you £100 off the cost of an alternative Thomas Cook holiday of your choice.

“If you booked a Thomas Cook holiday departing in summer 2018 and flying with Monarch Airlines, we have now added additional flight options departing from Leeds Bradford and Luton so we will be contacting you shortly to offer an alternative holiday.”