Well if it's a non UK hub, as is DUB, then the likes of SPL & CDG, to name but two, would be direct competition to Stobart's DUB route and, to a degree, their SEN route.
This is a problem with the airport and airline operator both being the same, in the old days I worked for Brymon Airways who operated both PLH & NQY airports, the airports were to never to develop to their full potential because they were a closed shop.
Similarly Lands End and Skybus, I understand the helicopter operation wanted to relocate to LEQ but Skybus told them to Foxtrot Oscar, and just how many turboprop operators is SEN attracting when they have Stobart Air in-house who can operate there cheaper than any competition?