what part of lgw crew being part of a mainline base and being part of the NSP is nonsense?
The majority of "mainline" cabin crew took the company's offer and went to Heathrow
before the introduction of the new "MidFleet" contract! If you look at the new contracts, they are under "BA - Gatwick and the Regions".
The cabin crew belonging to BA mainline and, thus coming under NSP agreements, are few indeed! For Flight Crews, those with contracts prior to September 2003 will be under BA Mainline, those who joined after will be "BA Gatwick and the Regions".