The redevelopment of Euston Station for HS2 will slash the number of platforms by a third, devastating commuter services. This little nugget wasn’t mentioned at the launch of the rebuilding plans, and badly undermines HS2’s main justification, that it will free capacity on the existing West Coast Main Line for new commuter and ­inter-city trains.

Though HS2 will supposedly release space on the line itself, it will be of little value, since fewer conventional trains than now will be able to get in to Euston, the main destination for passengers.

HS2 documents show that in its final state Euston will be left with only 13 conventional platforms, down from 18 now. Other sources suggest the number of conventional platforms could fall to as few as 11.