The Davies Commission is currently looking at this whole area as well as bilateral agreements !
Airline A, a Foreign airline applies for Shanghai - Manchester
Airlines B and C based in UK want reciprocal rights BUT want them from London as they have no interest in Manchester.
Airline A has a rethink they don't want to end up with a "regional flight" whilst Airlines B + C end up operating from the UK Capital.
Result ; Airline A backtracks !
Manchester which can support the service loses out ....and so it goes on and on and on................due domination of UK airlines at Heathrow !