LHR
Domestic routes to LHR and London from the regions are in decline and this will continue.
If passengers are going to London the train is avaiable.
The future for the regional airports is connections into euro hubs ie. AMS and FRA and this is what should be pushed for. The connections are often easier and better.
The important think is to keep the transit passengers departing but not via London
In the long run it could be a blessing.
Centre cities