Airlines and aerospace firms have called on Brussels to allow Europe’s air safety watchdog to plan for a no-deal Brexit, amid fears that flights could be grounded.

The European Aviation Safety Agency (Easa) is currently banned by the European Commission from holding emergency talks with the UK to keep aircraft flying in the event of no deal.

That means regulators at Easa have been unable to begin contingency planning with their counterparts at the Civil Aviation Authority — or even discuss it with them.

A letter sent last month by Easa’s stakeholder advisory body — comprising Europe’s biggest aerospace and airline companies — warned Easa that it was “essential the agency develops and enacts a mitigation plan”.

The letter, seen by The Sunday Times, reflects growing concern at companies from Airbus to easyJet that jet engines might not be certified from next April, grounding thousands of flights.

Airlines have already been forced to insert Brexit clauses into tickets.

The letter reportedly said: “Given the potential consequences of the UK leaving the EU . . . without all appropriate steps being taken, we believe this matter should be a priority for the agency and should not wait until the outcome of the negotiation is more certain.”