Introduction

The separation of powers is considered to be a self-evident principle of constitutional law in most democracies. However, as the case of the United Kingdom shows, a well-functioning democracy can do without it. The unwritten constitution of the UK is based on the sovereignty of the King in Parliament, which cannot be opposed by other institutions such as the courts. In political reality, however, Parliament is expected to respect constitutional conventions underlying the values and principles of the constitution, such as democracy, respect for minority rights and the rule of law. As Möllers has noted, conventions help to render the legislative decision-making process to ‘remain open in its results’ since they can be ‘changed or ignored at any time’. Yet conventions are in practice generally obeyed on the basis of ‘the same respect of the majority for the minority and the insight that today's majority may very well turn into tomorrow's minority’. In this traditional model, the legislative supremacy of Parliament is thus primarily curbed by political rather than by legal arrangements.

The enactment of the Human Rights Act 1998 (hereafter: HRA ) has put the regime of Parliamentary sovereignty increasingly under pressure. The HRA , which was enacted to give legal effect to the European Convention on Human Rights (ECHR) in the UK, has enhanced the powers of the judiciary significantly at the expense of the legislative and the executive branch. The Act has obliged the courts to interpret all primary and subordinate legislation compatibly with ECHR rights under section 3. If such an interpretation is not possible, the judge may issue a declaration of incompatibility under section 4. The courts do not have the ability to strike down Acts of Parliament; only Parliament itself can amend legislation violating human rights. The declaration of incompatibility thus gives the last word to Parliament and is therefore considered to be ‘sovereignty-respecting’.

The declaration of incompatibility seems to be in effect, however, very similar to a judicial strike down power. Parliament has almost always complied with declarations of incompatibility issued by the courts, because in practice it seems to be too difficult to ignore them. Hence, an emerging convention of compliance with declarations of incompatibility under section 4 of the HRA could be observed.