My understanding (only limited) of French Airspace organisation is that if your airway is going through a TMA then you are handled by the approach control unit rather than the area control. So if you are on a 'low' airway out of France you will be handled by the local unit (i.e. Lille) rather than the area. These local units seem to have limited ability to hand off to London Control, which can result in flights being handed to London Information and then unable to regain their Class A airspace IFR clearance. On in particular was a Jet Prop out of somewhere like LFAT that was levelled at FL090 (on the way to something like FL250 - for a trip to the North of England) for the handoff from France to the UK. They were handed to London Info and then had to stooge around London at low level.