On 1 February, the House of Lords Constitution Committee took evidence from Professors John Bell, Paul Craig and Alison Young on the likely constitutional implications of the ‘Great Repeal Bill’. The ‘Great Repeal Bill’ is not to be confused with the European Union (Notification of Withdrawal) Bill, which is currently before Parliament. The latter Bill was introduced into Parliament in response to the UK Supreme Court’s judgment in R (Miller) v Secretary of State for Exiting the European Union  UKSC 5, which held that the process under Article 50 of the Treaty on European Union, whereby the UK will withdraw from the EU, cannot be triggered without an Act of Parliament. The EU (Notification of Withdrawal) Bill — which consists of only one substantive clause — simply authorises the Prime Minister to trigger Article 50.
The Great Repeal Bill, which is not yet before Parliament, will be a far more complicated affair. It will provide the legal basis for the task of disentangling UK and EU law. It will do so, the Government has indicated, in two main ways. First, it will repeal the European Communities Act 1972 — a step which, on its own, would remove much EU law from the UK legal system (although EU law that has effect in the UK independently of the ECA, such as EU law that has been implemented by enacting or using powers conferred by other primary legislation, will not be affected by repeal of the ECA). Second, the ‘Great Repeal Bill’ will take the EU law that will no longer have effect under the ECA and will convert it into domestic law. The intention is that legal chaos will thereby be avoided by allowing for an orderly process that will inevitably be time-consuming. That process will involve determining which parts of the domesticated body of EU law should be kept, which should be jettisoned and which should be amended. The proposed scheme of the Great Repeal Bill will allow that process to be undertaken over an extended period of time following the domestication of EU law by the Great Repeal Bill.
This proposed process raises profoundly difficult legal and constitutional questions concerning, among other things, the range of EU laws that can be sensibly be domesticated, how those laws will be identified, how EU laws that need to be adjusted to make sense post-Brexit will actually be adjusted, the respective roles that Parliament and the Government will play in relation to such matters, and the degree of oversight that the former will exercise over the latter when it exercises the extensive delegated powers that the Bill will almost inevitably confer. In its evidence session, the House of Lords Constitution Committee explored these issues with its three witnesses, whose evidence makes plain the monumental scale and astonishing complexity of the task that lies ahead. A video recording of the evidence session can be accessed here.