WHBM,
Air France are the only ones with the A318 who go to LCY at the moment but as the BAe 146 and Avro RJ are now out of production, I would have thought it might get Swiss and Lufthansa Regional to look into using it. Swiss and Lufthansa both go there today with the Avro and both have A320 fleets already. It could make sense, couldn't it? That could, in the end, push BA to go that way as well...