It sounds like you may well have needed to actively request airways re-entry on this occasion...not because you should have or needed to but just because as with any ATC unit different controllers sometimes have different expectations of what the aircraft needs/is expecting...
Although I probably did not need to I would always ask on initial contact with London Info if I needed airways re-entry something along the lines of...
"G-xxxx requesting basic service and in due course onward airways clearance from (wherever my flight plan indicated) in accordance with my flight plan"
London Info would then get talking to whoever it was necessary to...
Last edited by Contacttower; 19th Sep 2013 at 08:01.
What circumstances permit you to enter controlled airspace without a clearance? If you're outside and want to come in, you have to ask.