Pilots' sick days could be used as factor when easyJet decides who to axe as part of a wave of redundancies, in a move branded "outrageous" by trade unions.
The airline will examine staff sickness records as part of a matrix that will also look at lateness and whether they failed to show up for work, as it seeks to determine the workers to lay off to cut costs.
Pilots' union Balpa said the system was “completely unacceptable in a safety critical-industry where pilots are legally required not to go to work if they are unfit to do so”.
In a letter to members, it said: “Punishing pilots for being sick or unfit to fly is outrageous and could significantly harm easyJet’s previously successful and well-regarded flight safety culture.”
EasyJet wants to sack more than 700 pilots as the airline reacts to the collapse in demand for air travel caused by coronavirus.
The law requires pilots to stay on the ground if they “know or suspect their physical or mental condition renders them temporarily or permanently unfit” because of injury or sickness, taking medicine or having treatment or surgery which may affect their ability to fly. Pilots can be fined or even jailed for ignoring the rules.
Brian Strutton, Balpa general secretary, said: “Flight safety is built on a culture of openness and not fear of repercussions. This is a fundamental tenet for everyone involved in ensuring our skies are safe.
“It is unnecessary and wrong that easyJet is intending to use sickness as a stick to beat its safety-critical staff. EasyJet has in the past rightly encouraged pilots to report in sick or fatigued if they are unfit to fly – that is in everyone’s best interest.
“To turn around and say that doing the right thing means you may lose your job could have a chilling effect on the safety culture in easyJet from now on.”
EasyJet said it is working closely with the union and redundancy proposals still at an early stage.
A spokesman said: "We would never put forward proposals which would compromise safety as we have an industry leading safety culture."
The airline is planning to lay off nearly one in three of its 15,000 workers, and a fortnight ago announced it will end ground operations at Stansted, Southend and Newcastle airports.
The airline has suffered a hit of almost £160m from Covid travel restrictions and raised £450m on thw stock market to shore up its finances.