A fresh legal challenge to the £43bn High Speed 2 project has failed.
The High Court dismissed a judicial review brought by campaigners HS2 Action Alliance and the London Borough of Hillingdon.
The pair had claimed that the government had acted against the EU Strategic Environmental Assessment Directive by not carrying out an SEA before acting to protect the route of the planned rapid rail line.
But the judge ruled that an SEA was not required as the safeguarding directions did not set the framework for development consent.
Transport minister Robert Goodwill said: “I invite interested groups to work with us through the Parliamentary process on making HS2 the very best it can be, and not to waste money on costly and fruitless court cases.
“The project had a huge vote of support in Parliament, recognising the importance of HS2 for the long term economy of the country. It will provide jobs, skills and free up space on our congested network for more trains and more passengers.”
Both the council and HS2AA said they would seek permission to take their claim to the Court of Appeal as well as considering other options.