EasyJet faces claims that it is putting passengers at risk by scheduling too many flights, leaving crew exhausted.

France’s pilots union issued an open letter to the budget carrier’s main shareholder, Stelios Haji-Ioannou.

It claims that staff are expected to work over legal flight time limits and intimidated if they refuse.

Arnaud Wiplier, head of the SNPL union, said: “A red line has been crossed and we are very shocked.

“The airline has eyes bigger than its stomach; the schedules are impossible.”

He added that if aircraft are scheduled to make six flights a day, then the last flight of the day will almost certainly be delayed or cancelled, the Daily Telegraph reported.

The union alleged that the crew were “exhausted” and were being “pushed to their limits every day” to keep up with their schedules.

Pilots are being asked to use their discretionary power to exceed the legal flight time limits to facilitate an unachievable program, to the detriment of passenger and crew safety,” the letter said.

“Certain flight captains who refuse, as is their right … are even summoned by the management to Luton to be intimidated. These are unbelievable practices.”

The combination of a heavy workload, typical summer delays from busy airports, and slow payment to staff has created stress all the way down the line, the union said.

As an example, the union referred to an incident in July when an airport worker in Nice came to blows with an easyJet passenger over delays as a “physical demonstration that a final stage of exasperation has been reached”.

EasyJet has said that it is “surprised” by the letter from the pilot union, adding that it had resolved the issue and continued to work closely with union members.

The airline added that it “would never compromise on safety”.

About 17 million people fly with easyJet in France each year.

SNPL vice-president Nicolas Frick said yesterday that progress had been made.

“SNPL and easyJet have reached a temporary resolution to the issues raised by the union last week and we are meeting later this week to continue our dialogue. Until that meeting, we will not comment further,” he said.