The Brexit negotiations will be monumental: so will the Parliamentary processes which will give effect to the results of the negotiations. Just as I was completing this article the result of the general election changed the political map. No single party now commands a majority in the House of Commons. Yet by March 2019 there may be another general election, with a different outcome. Whatever that may be, our processes, and the first principle of our constitution – the sovereignty of Parliament – are about to be subjected to the most gruelling examination. At present what can be said with certainty is that when the executive cannot command an overall majority in the Commons its power over the legislature is diminished. Nevertheless over the next few years the Brexit processes will provide a clear insight into the extent to which the power of the executive over the legislature may have increased, and where and how it might with advantage be curbed.

The ‘great’ repeal process

Before the election the Great Repeal Bill was anticipated. Even that simple title gave rise to controversy. Those opposed to the idea of Brexit deplore the description, ‘great’. Such an adjective should not be applied to what they regard as political folly. As a description of its importance, however, the description is accurate. Nevertheless the title fails to convey that the proposed legislation is concerned with a two-stage process, of which ‘repeal’ is only the first. Whether the title will survive the new Commons remains to be seen, but if Brexit is to go ahead the proposal, which is essentially very simple and largely concerned with mechanics, is likely to survive.

The European Communities Act 1972 will be repealed, but so as to avoid chaos, all existing Community (EU) law will simultaneously be assimilated into domestic United Kingdom (UK) law. That vast body of law will remain in force until it is amended or repealed or replaced. The principle will apply to law promulgated by the EU which automatically became enforceable in the UK without any Parliamentary process, and EU law which was not directly effective, but was implemented in the UK by primary or secondary legislation on the basis of powers derived from the 1972 Act.

Among several outstanding issues, it is worth noting, first, that the decisions of the Court of Justice in the European Union (CJEU) will continue to bind our courts until we finally leave the EU, and that thereafter legislation will be needed to define the applicability of existing case law of the CJ EU and the relationship between that court and our Supreme Court. Second, many existing EU laws are concerned with topics which have already been ‘devolved’ to Scotland and Wales. In Miller [2017] UKSC 5 the Supreme Court decided that the Brexit decision itself did not require the assent of the legislatures in Scotland and Wales, but it does not follow as a matter of law that the Sewel Convention (that the Westminster Parliament will not normally legislate on devolved issues without the consent of the devolved legislature) would be dis-applied in relation to the Great Repeal Act itself and subsequent legislation. Each of these issues will inevitably be politically contentious, but legislative proposals which ignored them would be incomplete.

In essence, however, whenever the 1972 Act is repealed, (and irrespective of any conditions which may be attached to its repeal) EU laws will continue in uninterrupted force until Parliament (or the devolved legislatures) decide otherwise. Ignoring any primary legislation which may be enacted between now and the date of departure from the EU, the anticipation will therefore be that legislation will simultaneously repeal and confirm existing EU law.

Secondary legislation and scrutiny

There is one further, and in the present context, outstanding feature of the Bill. It will create power to ministers to proceed by way of secondary legislation. Beyond the political issues this will directly impact on Parliamentary processes. There are literally thousands and thousands of laws, covering not so much pages, as many volumes which will fall to be assimilated, and then repealed or amended. Ignoring the use of primary legislation for this purpose the Department for Exiting the EU estimates that somewhere between 800 and 1,000 statutory instruments will be required. Ordinary government will continue. Legislation to deal with issues like the economy, defence, the NHS, criminal justice and the environment, will not vanish. Rather, an overcrowded Parliamentary programme will come under additional pressures.

The government will have to decide its legislative timetable. This is a political question. What are the priorities? Which EU laws should be amended or repealed? By the time we leave the EU those political decisions will or should have been made. The second problem, with which this article is concerned, is constitutional. How are the proposals for repeal and amendment to be implemented? What, if any, scrutiny will be permitted? What level of scrutiny is appropriate, and what should the legislature insist on?

When it is proposed to proceed by way of primary legislation, however controversial it may be, there is no constitutional problem. An obvious example will be legislation which addresses border controls, and immigration, migrant benefits, reciprocal healthcare, and whatever, if anything, replaces freedom of movement under current EU law. True, there will be ample scope for contentious, rebellious, protracted and ill-tempered debates in both Houses, but the legislative process is clear. The scrutinising process, too, is familiar. The primacy of the Commons will prevail.

The obvious temptation will be to proceed by secondary legislation. The processes themselves are clear, but the level of scrutiny is negligible, and the time required minimal. Where secondary legislation is concerned with what I may describe as administrative issues, such as the practical means of implementing primary legislation or updating existing statutory instruments, in short when it addresses uncontroversial or largely uncontroversial matters, or ‘nuts and bolts’, the process of scrutiny can sensibly remain minimal. But by no means always. The number of pages covered by statutory instruments annually in the last few years (that is, without consideration of any repeal or amendment of EU law) has been in the region of 13,000 pages. The last time the Commons rejected a statutory instrument was in 1968. And it has become the fashion for primary legislation to grant legislative authority to ministers to use secondary legislation to overrule existing primary legislation, or to implement policy, rather than merely to provide for ‘nuts and bolts’ issues. If the Parliamentary processes had not already become inured to these Henry VIII provisions we should regard them unparliamentary.

A defining moment

In the context of the Great Repeal Bill concerns about the proposed use of secondary legislation and in particular Henry VIII clauses for Brexit purposes have already been expressed in both Houses. The House of Commons Procedure Committee demanded that the conversion of EU law into domestic law, and future changes to former EU law should be properly scrutinised ( In the House of Lords the Delegated Powers and Regulatory Reform Committee added its support, urging that ‘the appropriate balance of power between the Executive and Parliament’ was required to maintain the integrity of Parliament ( The House of Lords Select Committee on the Constitution, acknowledging the virtual inevitability of granting ‘relatively wide delegated powers to amend existing EU law…’, pointed out that without specific restrictions on their use the Great Repeal Bill would be likely to involve ‘a massive transfer of legislative competence from Parliament to Government’ and suggested that Parliament should consider ‘how best to limit and exercise oversight of … these extensive delegated powers’ (

The proposals in the Great Repeal Bill to use secondary legislation to enact much of Brexit (whether ‘hard’ or ‘soft’) will demand scrupulous Parliamentary attention.

This Bill, however, is only the start. The way in which Parliament eventually legislates for the Brexit process will define our constitutional arrangements for some decades. The obvious danger is that the combination of extreme complexity and proportionately limited time would complete the process of embedding Henry VIII clauses so deeply in our constitutional arrangements that the term would lose all its pejorative connotations. The alternative possibility, however, is that the legislature will insist on much closer scrutiny of proposals to enhance ministerial powers, and perhaps even more important in the long run, the way in which they are proposed to be exercised in secondary legislation. Perhaps indeed the sovereignty of Parliament may emerge enhanced.