Traditionally, the UK parliament has been legislatively supreme: it can pass or repeal whatever measure it wishes. Membership of the European Community and the World Trade Organization has fundamentally changed this situation. Parliament and government are both constrained in what they may do if their action would conflict with the principle of free trade, to the extent that, under EC law, the domestic courts may override the will of Parliament. Provisions which allow nations to introduce restrictions in order to protect public morality, or the life and health of animals, have not been effective in providing a basis for the introduction of animal protection measures. Amendments to the Treaty of Rome, recognizing the sentiency of animals, is an advance, but what difference it will make in practice is as yet unclear. The apparent inability of a nation state to give effect to the will of its citizens raises important constitutional issues: it has serious implications for democracy and the rule of law and undermines the legitimacy of the political process.