‘We are a political project’: how HS2’s costs have spiralled out of control

The Colne Valley viaduct is one of the most significant engineering works of the project. Photograph: HS2

Should the enormous engineering feat of HS2 become Rishi Sunak’s white elephant, these could be its expensive tusks.

At what was once a staging post but now looks like the end of the line, Old Oak Common, two brand new tunnel boring machines are to be buried underground, unused, ready for action – a mere £40m of kit that may never now drill the route’s last six miles east into central London.