The fast train to political oblivion

This country is so bankrupt (at least, that is what the Government tells us ad nauseum) that we can't afford to pay for higher education, care of the elderly, libraries, a properly-funded national health service and a thousand other services we had come to take for granted.
Yet we can afford to lavish £17 billion to shave ten minutes off the train journey from London to Birmingham.
There are several unanswerable objections to proceeding with HS2, the high-speed train line that will scar some of the most beautiful countryside in England.
There is the ruin of the environment and the destruction of lives and homes. Not to mention rural Britain having all the pain and none of the gain (such as it is).
But it is the economic argument against this crazed delusion of grandeur which is the killer.  Why should we spend so much money when we are told there is so little around so that a small number of businessmen and women can travel from London to Birmingham (nowhere else) very slightly faster?
Apparently this is David Cameron's passion and Philip Hammond, the Transport Secretary, has to persuade the nation that it is a Good Idea.  He is usally quite a good advocate but even he can't sell this lunacy.
It can be stopped because all the constituencies which will be affected are held by the Tories and some are going to be lost if HS2 pushes ahead. Add to those the Tory constituencies that could be lost because the NHS "reforms" will lead to their local hospitals being closed and you have a lot of worried and disaffected backbenchers.
If you were a Conservative MP, at what point would you openly question, if not rebel against, the wild policies being forced through by the leadership of a party which already doesn't have a majority?
No one will remember that HS2 was originally a Labour idea, dreamt up by Andrew Adonis, who history will remember with incredulity. But more about him some other time. And a lot more about HS2.