Campaigners have lost their latest legal challenge to the first phase of the proposed HS2 high-speed rail line.
Opponents of the link - between Birmingham and London - accused the government of unlawfully failing to carry out a strategic environmental assessment (SEA).
They said such an assessment might help to alleviate problems being caused to local people and businesses.
However, three Court of Appeal judges unanimously rejected the challenge.
The challenge was brought by HS2 Action Alliance (HS2AA) and Hillingdon Council in west London - which are both campaigning against the project.
They argued that an SEA was required before "safeguarding directions" could be made by the transport secretary to protect land along the route from planning applications for other, conflicting developments.
'Costly and fruitless'
Some of the land could be included without any proper debate or assessment of environmental impacts or alternative options, they argued.
However, Lord Justice Longmore, Lord Justice Sullivan and Lord Justice Lewison ruled that an SEA was not required before the safeguarding directions could be made.
Following the ruling, Transport Secretary Patrick McLoughlin pleaded for HS2 opponents - who have mounted a series of legal challenges to the scheme - to end their "fruitless" court cases.
"The courts have once again rejected a legal challenge against HS2 as they have done on repeated occasions," he said, adding that the government had now won 20 out of 21 challenges to the project.
"I invite interested groups to work with us to make HS2 the very best it can be, and not waste more public money on costly and fruitless court cases," he said.
The Court of Appeal ruling backed up the decision of a High Court judge made in August this year.