A UK High Court has ordered Monarch Airlines (1968) (London Luton) to return its slots at various UK airports to the UK's Airport Coordination Ltd. (ACL).

According to a court ruling issued on Wednesday, November 8, Lord Justice Gross and Mr Justice Lewis rejected Monarch's claim that the ACL was under a duty to allocate Summer 2018 slots to Monarch "by reason of historical precedence ('grandfather rights')".

The Justices said that in Monarch's case, the ACL was no longer entitled to reserve its decision on the Summer 2018 slots.

"That would be to sterilise or distort part of the market, to the potential detriment of third parties, for an uncertain period of time," they said.

As such, pending the outcome of an appeal by Monarch's administrators KPMG, the ACL is free to reallocate the slots Monarch had at each of London Luton, Birmingham, GB, Leeds/Bradford, Manchester International, and London Gatwick. However, while Monarch's legal team were able to secure a stay of the court's decision on slots at Gatwick and Luton until November 17, pending the administrators’ application for permission to appeal, the ACL said those of Manchester will return to the pool next week for reallocation.

If the ruling is upheld, it will be a significant blow to creditor firms, among which is former owner Greybull Capital, who had been hoping to use the slots' sale to recover at least some of their debts from Monarch.