AUTOGLIDE
The yields from regional airports are not enough to justify many airlines starting and running profitable longhaul routes from Manchester IMHO.
If you take BA's LHR op's a lot of pax come from all over the world to connect with the longhaul flights. Manchester does not have the feeder network for any airline to sustain a operation like this. Not as many pax as people think come from the London area to fly on BA flights. Infact i would hazzard a guess if LHR was in Manchester most pax would not notice a difference!