If you ignore the bmiBaby staff at Hastings House, probably no more than 300.
The majority are senior management, IT, Rev Man, procurement and other back office functions that would be absorbed by any other airline that may wish to buy it as a functioning airline. Regardless of what happens, there will be job losses. I know it is not what people want to hear but that is the sad reality.
The centre of gravity is LHR, the Castle is an unnecessary cost and no buyer wants it. Even if BA or VS were to get the airline, there will be job losses at front line staff level as well.
None of this is good news
