The two main trade unions representing staff at collapsed airline Monarch are preparing legal action over the handling of nearly 1,900 job losses.
Unite, which represents cabin crew and engineers, said it was launching a claim over the lack of consultation.
Pilots union Balpa said it was also seeking compensation for the “shabby” handling of the redundancy news.
Administrators KPMG said it had provided support to staff and already issued forms for redundancy payments.
Monarch Airlines ceased trading early on Monday, with 90% of its 2,100 workers made redundant.
The collapse of the 50-year old company is the largest ever for a UK airline and led to the cancellation of all its flights and holidays.
Staff were sent messages that day inviting them to face-to-face meetings at 09:00 BST or a conference call at 14:00, KPMG said.
KPMG has since faced criticism for Monarch staff being charged by their phone company to join the conference call.
The firm said the workers would be reimbursed for the charge – a move which Balpa welcomed, saying “common sense has prevailed”.
Brian Strutton, general secretary of Balpa, which represents 400 Monarch pilots, said: “Balpa can confirm that we will also be seeking compensation for the shabby way our members were notified of their company’s demise and their own sacking.”
Mr Strutton told the BBC that the union was already compiling a legal claim.
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The chief executive of failed airline Monarch tells Today projected losses were too great to stay operating
Unite said it would lodge employment tribunal proceedings over the company’s failure to consult the workers on redundancies.
The trade union also said the employers had not given the necessary 45-day notice or statutory pay.
“Unite is doing everything it can to assist former Monarch workers in securing new jobs, offering free legal advice and launching legal action to secure the compensation they are owed, as well as helping members find jobs with other airlines,” Unite national officer Oliver Richardson said.
KPMG said it sent redundancy pay letters to employees on Tuesday night, day two of the administration, which is “extremely fast for any administration, let alone one of this scale”.
It added that a number of the Monarch HR team had been retained to help “get as many people as possible back in to work as soon as possible”.
Source: BBC News