Passenger watchdog TravelWatch says any loss of air services to London Gatwick will be bad news for the Island.
Flybe has confirmed it's in talks with other airlines over selling its slots at Gatwick.
easyJet, which competes with Flybe on the route, is a possible buyer.
Bosses of both airlines were quizzed this week by a Tynwald committee looking at the Island's Open Skies aviation policy.
TravelWatch chairman Brendan O'Friel watched the sitting.
He says the loss of competition on a key route to the UK capital is a big concern:
Researching your Manx family history can be a very interesting and rewarding hobby. Trace your roots in the Isle of Man with our helpful of guide.
