All Monarch Airline flights from Birmingham Airport have been cancelled after the airline went into administration.
Monarch Airlines has ceased trading with immediate effect, meaning all flights from the UK will not be rescheduled.
A spokesperson from Birmingham Airport said:
In a statement Monarch CEO Andrew Swaffield apologised to all Monarch Airlines and Monarch Travel Group employees, telling them to "hold their heads up high and be proud of what you achieved at Monarch".
It is unclear how staff working for Monarch at Birmingham Airport will be affected.
The airport is asking customers to visit the dedicated website set up by the CAA - monarch.caa.co.uk - which contains a guide for anyone impacted.
There is also a dedicated phone line: 0300 303 2800 from in the UK, and +44 1753 330330 from overseas.
Foreign Office staff will be at affected airports to assist vulnerable British travellers with specific needs.