Regional carrier Flybe says it hopes common sense will prevail over the UK’s Brexit negotiations with Europe.
The airline’s chief commercial officer Roy Kinnear says the big fear is that flights could be stopped next year if there is no agreement.
The UK is just eight months away from the deadline for leaving the EU and yet there are still no political or commercial agreements in place including a deal on flying rights.
Kinnear told BBC South News: “The big fear has to be that at the eleventh hour there is a complete cessation of air travel. That is our ultimate worry.
“Customers are used to buying flights in advance. But we cannot stop selling now waiting to see because one would hope common sense will prevail at the end of this.”
Concerns raised by Exeter-based Flybe, the largest carrier operating at Southampton airport, echo those of Budget carrier Ryanair about the impact of Brexit.
The UK government has said a deal on aviation and flying rights is a key priority but there remain concerns about what a no-deal Brexit would mean for airlines.
The BBC said airlines like Flybe are basing their future plans on guesswork.