The Westminster Parliament's Formal Sovereignty in Britain and Europe from a Historical Perspective

23 Feb 2018

In the historical backdrop to domestic British debates about Brexit has been tension between two contrasting and competing conceptions of the Westminster Parliament’s sovereignty. In issue has been whether or how parliamentary sovereignty has been subject to constraint, to limitations of form or substance, in strict legal theory or in practical politics. The tension was the product of a doctrinal dichotomy that Albert Venn Dicey introduced in the late-nineteenth century. He introduced it in attempting to juridicalise or juridify the constitution in his foundational and multi-edition textbook The Law of the Constitution. The dichotomy was, on the one hand, of a formal legal conception of Parliament’s sovereignty as limitless in theory and, on the other hand, of a substantive political conception of its sovereignty as limited in actuality. The tension between these legal and political conceptions has been manifest since then in various formal exercises of Parliament’s sovereignty that have impaired its substance. They include parliamentary enactments that conferred self-government in the process of decolonisation, that granted the executive powers to amend parliamentary legislation through “Henry VIII clauses”, and that delegated various governing powers in devolution. The tension has also been manifest in the enactment of the European Communities Act 1972, by which the Westminster Parliament made domestic legal provision for the UK’s original inclusion in the European Communities. The tension was exacerbated by the unqualified assertion of the unconditional supremacy of Community law by the ECJ, both before and after the 1972 enactment. Through judicial minimalism or false economy − failure to acknowledge, explain and address pressing issues at stake − in the response of the highest British court to the ECJ’s assertion of supremacy, problems in the Westminster Parliament’s legal and political sovereignty were left unresolved and vulnerable to serious objection. They contributed to making the UK’s continued membership of the EU precarious and unstable. The doctrinal and constitutional options and implications for the UK are challenging, as are various searching questions for the EU.