Chief executive Shai Weiss said the airline was being “forced to fly almost empty planes or lose our valuable slots” after passenger demand plummeted due to COVID-19.
Under European law, carriers have to fill their slots at major airports such as Heathrow at least 80% of the time or they risk losing them.
While the slots are assigned by airports for free, they are valuable commodities and are often worth millions of pounds.
The rules have led to passengers across the world travelling on nearly empty flights, as well as reports that carriers are operating “ghost flights” without any passengers at all.
Mr Weiss said: “Given the almost unprecedented impact on global passenger demand, the UK slot coordinator and the European Commission need to now urgently relax the rules for the whole summer. Common sense must prevail.”
There has been some temporary lifting of restrictions but only on slots used to fly to China and Hong Kong.