British Airways has furloughed thousands of its staff, citing delays to travel as the reason behind its decision.
The airline confirmed on Thursday that a large number of its workers - including management staff - have been put back onto the scheme.
Workers were being brought off furlough ahead of the summer holiday period after the Government set May 17 as the date for the restart of international travel.
However, no top holiday destinations are on the green list, meaning travellers returning from places such as France, Spain and Italy must quarantine at home for 10 days.
A large number of BA staff were already on furlough before the latest furlough decision took place, it is understood.
The firm has called for the Government to open international travel "as soon as possible" and add "low-risk" nations such as the United States to its green list.
It confirmed reports that more members of staff are to go onto the flexible furlough scheme and work part-time.
A BA spokesman said: "Like many companies we're using the furlough scheme to protect jobs during this unprecedented crisis."
It comes as Airlines UK, a trade association representing UK carriers, argued furlough support for aviation workers should be extended until April next year.
In a letter to Chancellor Rishi Sunak, the industry body said airlines have made pre-tax losses running into billions of pounds and announced more than 30,000 job cuts during the coronavirus pandemic.
The furlough scheme, which pays up to 80% of wages, is due to end on September 30, but the letter called for it to be extended until the end of April 2022.
British Airways welcomed an announcement on Thursday that Prime Minister Boris Johnson and US President Joe Biden will launch a taskforce to make recommendations on safely restarting international travel.
BA boss Sean Doyle said the announcement was "a step in the right direction", but added: "We are now at a critical point and need action without delay, including clear criteria and a timeline.
"Anything other than this could result in tough consequences."