SEN - or any other airport - will have to be very persuasive if it wants to get its hands on Govt cash
If the company owning / operating an airport goes bankrupt, the physical infrastructure stays in place. Even airports like Blackpool, Manston and Plymouth, remain in place but largely mothballed and, if demand were to rise, could be made usable again without enormous expenditure. Yes, things like landing systems will need work - but if air travel demand returns, then some company will likely emerge to buy the airport site, or a lease on it, and get the airport going again. It is very unlikely that a council with a potentially viable airport in its area that could boost the local economy would grant permission for the airport to be closed permanently and completely covered in housing
If Stobart went bust.... would you really expect SEN to become a huge housing estate ?