When Easyjet ramped up its Gatwick operations years ago Luton lost ground. It is only in recent years after an agreement that Easyjet increased its presence at Luton probably in part due to not having enough slots at Gatwick.
If Wizz gains enough slots at Gatwick any expansion that would have come Luton’s way will move south of the Thames. Not good for the Council that wants to double passenger numbers with an existing terminal built on the cheap by a franchise holder that was never interested in building quality but just wanted more floor space in the belief that passengers had no choice.