Dinahmo I am not sure about the French being happy to have their houses compulsorily purchased for the TGV lines. More, I think, that the French government just ride roughshod over all objections, they do not bother with tunnels but just build their lines up hill and own dale over open country and then build really powerful engines that can cope with the inclines.
France is also a much larger and squarer country than the UK, so there are real advantages in having long very fast railways. I have benfitted from the train that enables me to get from London to Marseilles in about 7 hours, over 600 miles, but except for London to Inverness, we do not have these great distances in the UK and Great Britain gets narrower and less populated, the further north you go, so the potential market is small.
HS2, was a disaster from the start, but it has gone so far now that it has got to be finished - and by finished i mean go to Manchester, but beyond that, the money should be spent on improving the existing infrastructure and improving rolling stock, timetables and stations to make travelling aroud the north of England and into Scotland, smoother, quicker and assle free.