Thomson and First Choice opened 620 shops on Sunday to help customers rebook their holidays as the volcanic ash cloud continued to make the UK a no-fly zone.

Retail sales and operations director Kathryn Ward said the decision was taken to open the shops when it that emerged no flights would be leaving or entering the UK today.

The 620 shops opened at just 24 hours’ notice, with many staff working from 7am until 11pm. Normally, about 350 retail stores are open on Sundays.

Agents dealt will all bookings made in Tui’s retail stores, call centres or online. Shops had a constant flow of customers all day, with some people queuing outside the door.

Customers booked to travel were given the option to rebook an alternative holiday or flight without paying amendment fees or take a full refund.

“Staff gave up their own time and worked six-day weeks,” said Ward.

“This really highlighted the value of having such a large shop network as it also eased the pressure on our incident line.”

Ward said customers had been understanding about their holidays being cancelled.

“Many people panic and want to speak to someone face to face. Everybody is disappointed and frustrated, as we all know how much planning goes into a holiday, but they know it’s not our fault,” she said.

“While there have been tough times in the past, there has been nothing quite like this. I can’t remember a time when we had to take such extreme action.”

Retail staff are also standing by to meet Tui customers at airports or ferry ports as they return from abroad. Tui Travel is arranging to bring 5,000 people back from Spain by coach and ship.