It is imperative that HS2 responds directly to Hillingdon Council’s independent report on a tunnel extension, that draws two powerful conclusions. Firstly, a tunnel extension across the Colne Valley is feasible. Secondly it can be done at effectively the same price as the current, very damaging plans. More details of which can be found here
My concern is that they will not do so with an open mind. So I have written to the Chairman of HS2 to make that point strongly You can read the letter here; David Higgins letter feb 2015.