The Supreme Court has dismissed an appeal brought by HS2 Action Alliance Limited (and others) against the Government’s proposals in relation to HS2.

In a judgment handed down this morning, the Supreme Court dismissed both of the appellants’ two grounds of challenge to the Government’s procedural proposals as to how it would obtain development consent for a high-speed link between London and the north.

The first of the appellants’ grounds was that an environmental impact assessment should have been carried out in relation to the Government’s proposals as to the procedure for obtaining development consent (which proposals were set out in a command paper, “High Speed Rail: Investing in Britain’s Future – Decisions and Next Steps“).  The appellants claimed that the Strategic Environmental Assessment Directive (the “SEA Directive“) imposed a requirement for any constraint on development consent, prior to the grant of that consent, to be subjected to an environmental impact assessment.

The Court found that the Government’s proposals did not amount to a constraint on development consent, and thus did not fall within the scope of the SEA Directive.  As Lord Carnwath explained at paragraphs 38 and 39 of his judgment, the Government’s proposal:

does not in any way constrain the decision-making process of the authority responsible, which in this case is Parliament. … Formally, and in reality, Parliament is autonomous, and not bound by any “criteria” contained in previous government statements.

The second ground was that the UK’s parliamentary procedure for hybrid bills – which combine elements of the parliamentary procedure for public bills and private bills – was incompatible with EU law (specifically, the Environmental Impact Assessment Directive, or “EIA Directive“).

In his judgment, with which the other six justices agreed, Lord Reed began by emphasising that it was for the UK courts to resolve potential conflicts between UK constitutional law and EU law.  At paragraph 79, he stated that:

If there is a conflict between a constitutional principle, such as that embodied in article 9 of the Bill of Rights, and EU law, that conflict has to be resolved by our courts as an issue arising under the constitutional law of the United Kingdom.

On that basis, Lord Reed did not consider that the Court was under any obligation to make a reference to the Court of Justice of the EU (“CJEU“).  Referring to a number of CJEU judgments, including Nomarchiaki, Lord Reed emphasised at paragraph 117 that:

The court has made it clear that it expects national courts to apply the principles which were established in those judgments in the context of their own national systems.

The Court then went on to reject the appellants’ argument that specific characteristics of the UK parliamentary procedure breached requirements of EU law.  The appellants had argued that the influence of the party whips (among other things) prevented proper public participation in decision-making in relation to projects with a significant environmental impact, as required by the EIA.  Rejecting this, the Court emphasised, at paragraph 110, the following:

The separation of powers is a fundamental aspect of most if not all of the constitutions of member states. … [T]he appellants’ contentions might pose a difficulty in any member state in which it would be considered inappropriate for the courts to supervise the internal proceedings of the national legislature, at least in the absence of the breach of a constitutional guarantee.

The Supreme Court’s decision not only allows the government to continue with its plans for HS2 but is also an important reaffirmation of some of the fundamental principles of UK constitutional law, including where questions of EU law are in play.