The Statute of Proclamations of 1539 was passed by the then Parliament at Westminster. It allowed King Henry VIII to issue proclamations which had the same effect as an Act of Parliament without the bother of actually having to be passed by Parliament. On Henry VIII's death in 1547 it was repealed and the procedure quietly forgotten. This has now morphed in modern parliamentary process into a power in an Act which allows amendments to be made to other Acts by secondary legislation, pithily known as a Henry VIII power. Parliament has a role in passing secondary legislation but the level of scrutiny given by a legislature, including the devolved legislatures, to secondary legislation is much less that that given to passing Acts so it puts the Government in a much stronger position and makes it less likely they will be challenged.
Nobody doubts that Brexit will mean a huge increase in the volume of secondary legislation passing through our legislatures in Westminster, Holyrood and Cardiff (and Northern Ireland if the current situation is resolved). There are different figures suggesting anything between 7000 and 17,000 pieces of EU inspired legislation which will require to be amended to make them work in the UK post Brexit. Even if the figure is on the lower end of the spectrum that is still a lot of legislation for a legislature to amend. To put those figures in context, in 2014-2015, which was a busy year, 1378 statutory instruments were laid in Westminster. The system is now going to have to accommodate a much larger number of legislative amendments than that over a relatively short period of time, and that is where the Henry VIII powers will come into play. They will save Parliamentary time by allowing amendments to Acts by the less time consuming secondary legislation process as opposed to following the much longer and more complicated process to pass an Act amending a predecessor Act.
The European Union (Withdrawal) Bill is full of Henry VIII powers allowing amendment of other primary legislation by secondary legislation. It also includes the most extensive of these powers which allows the EU (Withdrawal) Bill itself to be amended if the Minister considers it appropriate, which is not a very high test. This means that secondary legislation could in theory change or remove the safeguards in the EU (Withdrawal) Bill itself including sunset clauses, time limits, processes as well as altering other aspects of the Bill which will have been agreed by Parliament. The Government say they will not exercise these powers inappropriately and this is purely a belt and braces power in case they need to act fast in implementing aspects of the Brexit negotiations. This will certainly be the intention but who knows what implementation issues the future negotiations will bring.
Equally important is that the members of the legislature can amend Bills on their way to becoming Acts but the only option for secondary legislation is to accept it - or not. No amendments are possible. Annulment is the only remedy. It is however worth noting that the last time the House of Commons annulled a negative statutory instrument was in October 1979 and the House of Lords last such effort was in February 2000. It is a rare procedure. It is difficult to see the annulment procedure providing an effective remedy to any perceived abuse of the very wide Henry VIII powers by any Government. It is also worth remembering that the Sewel convention requiring devolved legislatures to be consulted if primary legislation will affect their legislative competence does not apply to secondary legislation. There is real scope for constitutional difficulty.
The use of Henry VIII powers in terms of the EU (Withdrawal) Bill is going to affect all areas touched by EU law, however lightly. It is going to be up to all of us to influence those who will be instructing and drafting the secondary legislation exercising the Henry VIII powers as best we can. By the time the secondary legislation is published it may be too late to influence it in any real way.
Henry VIII was an absolute monarch and wouldn't recognise or approve of the power of the parliamentary democracy we enjoy today in the UK but that doesn't mean that his nominative legislative legacy is not fraught with difficulty and raises real concern as to how Parliamentary oversight of the Government's executive actions is going to work. It may sound like a technical legal difficulty for lawyers to sort out, but ultimately it affects the practical ability of our elected representatives to keep a real check on Government secondary legislation to protect the interests of us the citizens in delivering a successful Brexit. We elected our representatives. No one elected Henry VIII.