The British Airline Pilots’ Association (Balpa) has written to the investment firm saying it has “an even greater responsibility” to reimburse Monarch ex-employees which it claims are “suffering huge financial loss of back pay and other monies owed, let alone the loss of their entire livelihood”.

The letter follows reports that Greybull has pledged proceeds from Monarch asset sales to the government to help cover the estimated £60 million repatriation operation in the wake of the airline’s collapse on October 2.

Balpa, which represents around 400 pilots who lost their jobs as a result of the Monarch collapse, believes any money made in the sales should go to former employees first.

In a separate letter to transport secretary Chris Grayling, Balpa general secretary, Brian Strutton also questioned if the heavily-criticised Monarch repatriation bill could have been avoided.

He suggested that instead of instantly shutting down operations upon the airline entering administration, Monarch’s remaining funds could have been used to wind down the business slowly – with Monarch flights being used to bring home overseas passengers.

Strutton said such an approach would have allowed Monarch staff to end their tenure with “dignity”.

He said: “Employees could have carried on working, bought all the passengers home and had all outstanding monies paid to them.

“If there is any sense of conscience it should surely be to pay what is owed to employees.

“It would be totally unfair and unjust if Greybull benefited from being ahead of the creditor queue, then passed its proceeds over to the government while employees suffer huge losses.”