The government's consultation on compensation for homeowners affected by the High Speed 2 (HS2) rail route was "so unfair as to be unlawful", a high court judge has found.
Mr Justice Ouseley rejected nine of the ten challenges against the HS2 plans but upheld one on the property compensation consultation.
The government has already announced it will not appeal the ruling and that the Department for Transport will hold another consultation without affecting the HS2 timetable.
"The government must now go back to the drawing board and rethink its approach to compensation," Hilary Wharf of High Speed 2 Action Alliance (HS2AA) said.
"There are many better compensation alternatives which would help all those up and down the country trapped by HS2."
About 172,000 properties lie within 0.6 miles (1km) of the first phase. They are expected to face so-called 'HS2 blight', as their value is hammered by the project.
"It is right that this vital infrastructure project can now proceed once ministers have re-run the part of the consultation that they botched," shadow transport secretary Maria Eagle said.
"We've now had nearly three years of dither and delay over HS2 which must now come to an end. It is vital that the government now gets on with introducing the necessary legislation to make this scheme a reality on the ground."
Four protest groups brought the five judicial reviews. The judge rejected the argument the line breached European environmental regulations.