The airspace needs reviewing now. It was underway I believe by one of your senior managers (he goes everywhere with a clipboard) until it was mothballed and put into the too hard pile.
The TMA airspace review / redraw - which every ATCO that works in it (Area and airports) wants to see happen - was put on hold by the bean counters down south.
Basically any money spent on it wouldn't see a return in reduced delays - so its been put on hold.
May I suggest the pilots and airlines start lobbying on fuel / environmental grounds.
The whole things needs an etch-a-sketch shake and started again.