HS2 protesters have lost a legal battle with the government over the £43bn project.
The campaigners had accused the government of unlawfully failing to carry out a strategic environmental assessment (SEA) on phase one of the scheme, between London and Birmingham.
They argued that an assessment could help alleviate problems for people living along the proposed route.
But all three appeal judges today unanimously rejected the challenge, supporting an earlier High Court verdict.
In a statement, they said: “The safeguarding directions do not set the framework for development consent for projects within the HS2 safeguarding zone. In turn, no SEA was required before making the safeguarding directions. The Court of Appeal supported the earlier decision of the High Court.
“The appellants’ submission is flawed because it looks at only part, rather than the entirety, of the decision making process for development consent within the safeguarded zone.”
A Department for Transport statement said: “This judgment confirms once again that we are on the right track with HS2.
“HS2 is a vital part of our long-term economic plan. By improving connectivity, freeing up space on our existing network, boosting local skills, generating tens of thousands of jobs and helping rebalance our economy, it will have a transformational effect on the UK and secure the country’s future prosperity.
“We are building on the best practice shown in HS1, the Olympics and Crossrail to minimise environmental impact during construction. The Government is determined to minimise the environmental impacts that go with a major infrastructure project of this kind. HS2 Ltd has committed to limit noise impacts, to plant 4 million trees, to link important habitats together and seek to achieve no net loss to biodiversity.”