These 3 airports VLC, SVQ, BIO still not served from London airports with BA. They are the third, fourth and fith biggest metropolitan areas in Spain, and also important touristic cities/regions being Seville the third most visited city in Spain, Valencia the fourth and Bilbao the sixth.
Although there is lowcost competition from VLG, EZY and RYR, I think there is still a gap to grow mainly in VLC and SVQ as short haul destinations from LGW.