Blackburn v Attorney General  2 All ER 1380
Affirmed Parliament’s right to sign the Maastricht Treaty and thus voluntarily give some of its powers to the EC, despite the principle of Parliamentary sovereignty.
The claimant, Blackburn, asserted that the decision by Parliament to allow Britain to join the Economic Community and sign the Maastricht Treaty was illegal as it diminished their own sovereignty, and violated the theoretical conception of the ‘Queen in Parliament’, whereby all power is vested in the Crown and subsequently in Parliament. Thus, Blackburn sought a judicial review.
Whether Parliament had the authority to enter Britain into the European Community and voluntarily relinquish some of their own powers.
The Court of Appeal held that Britain’s decision to join the Economic Community did not amount to an illegal surrendering of Parliamentary sovereignty. Further, the very nature of Parliament’s supreme sovereignty meant that they could ‘enact, amend and repeal any legislation it pleases’, and as Parliament voluntarily elected to recognise EC law, this was not an intrusion on their sovereignty. Moreover, it was beyond the jurisdiction of the Courts to perform a judicial review on Parliament’s rightful exercise of its prerogative powers. Furthermore, as Parliament was unable to bind successive Parliaments, any delegation of powers to the EC was reversible. Notably, the decision was not unanimous with Lord Denning dissenting on the grounds that the Statute of Westminster 1931, which granted powers to British dominions, meant that Parliament was not empowered to place subsequent reductions on the powers given to the dominions by giving them to the European Community.