Key facts of the case:
X appealed against a decision ( EWCA Civ 920,  P.T.S.R. 1194) dismissing their challenges to the Secretary of State's proposals for the high speed rail project, HS2. The Secretary of State had issued a Command Paper or "next steps document" (NSD) detailing the project and proposing a Hybrid Bill procedure in Parliament to implement the scheme. X argued that (1) NSD should have been preceded by a strategic environmental assessment under Directive 2001/42 (the SEA Directive) as it was a "plan or programme" within art.3, and the SEA Directive had to be interpreted to ensure conformity with the Aarhus Convention 2001 art.7; (2) the Hybrid Bill procedure did not comply with the requirements of Directive 2011/92 (the EIA Directive), as the party whipping of the vote and the limited opportunity to examine the environmental information during the Parliamentary process prevented effective public participation as required by art.6(4).
106. Furthermore, Parliamentary parties are recognised as playing a legitimate role in democratic decision-making in other member states besides the United Kingdom (see, for example, article 53a of the German Basic Law, and the Federal Constitutional Court's judgment of 10 May 1977 on the Weapons Act 1972, BVerfGE 44, 308, paras 35-37). Their role at European level is expressly recognised in article 10(4) of the Treaty on European Union, which provides that "political parties at European level contribute to forming European political awareness and to expressing the will of citizens of the Union". Article 12(2) of the Charter of Fundamental Rights of the European Union is in similar terms. The role of political parties in democratic decision-making at national level is no less important.