If they were going to go down the all J model I suspect it would be out of LHR, the current focus and business model at LGW is more leisure, in both long and short haul.
wasnt actually what i was suggesting, i meant that the A318's could be delivered in all J config and used at London City Airport to expand the current all business offering which offers 2 JFK services on A318's.
it could well get put under a BA order for LGW as the LCY services on the Airbus are crewed by Gatwick staff.