When we talk about the real estate that is Southend Airport, unless the world changes dramatically, then an airport of sorts it will remain. I've seen it suggested here in the past that the land could be developed for housing or industrial use, but it's a non-starter. So if Stobart fail in regards to achieving their ambitions, they won't be able to run down the place, turn it into an eyesore, obtain planning permission for a thousand luxury homes and sell the asset at a huge profit. They really are stuck until and unless someone wants to take over the airport and are prepared to pay handsomely for the privilege. Southend Airport is not Carlisle.
I also understand that the local authority own the freehold still.