@Sqad
Pragmatically, I accept that you're right: both parties are stuck in a fork and cannot deviate from keeping this promise to the electorate. Or at least trying to. When things fall over, a patch will be applied as necessary and if it means a solution along the lines of dentistry then they know the electorate will shrug their shoulders and accept it.
While I accept that pooling experts at major urban centres improves the excellence of specialist units, I live on a peninsular. Although I am not going to be affected, the neo-natal care unit which was smack in the middle of Pembrokeshire (~30,000 population) was closed and they have to go to a "bigger, better" unit, in Carmarthen, which is 30 miles east. 20p/mile = £12, per round trip and wages aren't exactly rip roaring in this neck of the woods.
Free at the point of use? Hardly. Service? Yes but not conveniently nearby any more. What unit will they "centralise" next?