Hillingdon Council and campaign group HS2 Action Alliance (HS2AA) are continuing their legal challenge against the Government over safeguarding directions for HS2.
In June, the council and HS2AA brought a fresh judicial review challenge to the High Court, challenging the decision by transport secretary Patrick McLoughlin to issue safeguarding directions without first undertaking a Strategic Environmental Assessment.
Safeguarding is designed to protect land which has been earmarked for major infrastructure, in this case HS2, from conflicting developments which might otherwise occur.
The campaigners said the directions were fatally flawed and should be quashed.
But at the High Court in August, Mr Justice Lindblom dismissed all grounds of the claim, but said: “This is not the first claim for judicial review in which the Government’s promotion of HS2 has been challenged. And it may not be the last.
“HS2, if it is built, will transform the environment along its route. On any view, its impacts on the environment will be significant.”
Lord Justice Longmore, Lord Justice Sullivan and Lord Justice Lewison will be urged by the campaigners to overturn his decision at the Court of Appeal today, Tuesday, November 25.
Speaking ahead of the hearing in June, council leader Ray Puddifoot said: "Despite the Government telling us that resistance is futile, we will continue our fight against this flawed plan, however long it takes.
"This is not a done deal and we will continue to challenge the Government."