These long haul routes should have been from Manchester, vast untapped demand.
This quote from the Independent gives the answer:
Bjorn Kjos, chief executive of Norwegian, revealed the routes at a press conference in London today. He said that low-cost long-haul could work only as an extension of a successful short-haul network, and only with the right aircraft. "The fuel efficiency and also the utilisation of the Dreamliner are much better. If we fly the next best aircraft in the market the extra cost would be £5m a year."
Mr Kjos said that he expected many European travellers to fly to Gatwick in order to transfer to transatlantic flights: "People will 'self-connect'. I believe that's the future".