At the same time, Nimmo, Tucker and Steve Absolom from KPMG have been appointed joint administrators to Monarch Travel Group Ltd, which employs a further 153 staff.  The group’s engineering operation, Monarch Aircraft Engineering Ltd is not in administration and continues to trade normally.

Blair Nimmo, partner at KPMG and joint administrator to the companies, said: ‘Mounting cost pressures and increasingly competitive market conditions in the European short-haul market have contributed to the Monarch Group experiencing a sustained period of trading losses. This has resulted in management appointing us as administrators in the early hours of this morning.

‘While this timing is unusual in insolvency situations, it was necessary for the appointment to be made once all Monarch aircraft were on the ground. This only occurs in the early hours of the morning. Once the company entered insolvency, the air operating certificate it needs to be able to fly was effectively suspended, which is why all outbound flights were cancelled with immediate effect.’

The suspension of its certificate means all flights operated by Monarch Airlines from the UK, and all future holidays booked with Monarch Travel Group, are cancelled and Monarch will not be able to reschedule these flights or holidays.

All Monarch flights to the UK today and for the next two weeks will be replaced with alternative flights, organised by the Civil Aviation Authority (CAA) with assistance from the administrators.

Nimmo said: ‘Our primary focus for the next 48 hours is to work with the CAA to provide the infrastructure and information needed to help the government and CAA with the safe repatriation of approximately all the 110,000 customers who are currently overseas and due to travel back to the UK within the next two weeks.

‘This includes all those whose trip is not specifically covered by ATOL protection. The CAA has provided funding to enable the group to retain a number of employees to assist us with the provision of this information.

‘We will also be speaking to all of the group’s employees today, and commencing the process of returning the group’s leased aircraft fleet to its owners.’

The government has announced has stepped in with what transport secretary Chris Grayling called an ‘unprecedented operation’ to return passengers who would otherwise have been left stranded by a lack of capacity in the aviation market to deal with such a significant demand.

It is working with the CAA to build a temporary airline from scratch that would be one of the UK’s biggest carriers if operating permanently. Grayling described it as the ‘biggest ever peacetime repatriation’.

The response means the government has agreed that passengers will not be charged for repatriation flights. Work is underway to recoup costs from the ATOL scheme and card providers. Repatriation flights are for all passengers who purchased tickets with Monarch – irrespective of nationality.

Grayling said: ‘This is an unprecedented response to an unprecedented situation. Together with the CAA, we will work around the clock to ensure Monarch passengers get the support they need.

‘Nobody should underestimate the size of the challenge, so I ask passengers to be patient and act on the advice given by the CAA.’

Monarch comprises a scheduled airline, in-house tour operator and an engineering division. Together, the group offered airline capacity of over 6m sector seats and tour operator passenger volumes of over 200,000 per year. Founded in 1968, its headquarters are in Luton, and the airline and tour group employ approximately 2,100 people between them.

For more information on the current situation, passengers should visit the dedicated website monarch.caa.co.uk or call the helpline on 0300 303 2800 (UK) or +44 1753 330 330 (overseas).

Details of the government’s response and the actions passengers should take are here.