Blog of the International Journal of Constitutional Law

Entrenching and Undercutting

Adam Perry, Associate Professor and Tutor in Law, University of Oxford

Nick Barber has an article titled ‘Why Entrench?’ coming out in the International Journal of Constitutional Law (available on SSRN). Among other things, the article is about the kinds of entrenchment there are, the reasons there are for entrenchment, and how the two match up. I really like the piece: it’s clear and persuasive, with some fresh examples and a useful typology. Here I want to explore a point that Barber hints at, but doesn’t get into.


First, a quick summary of Barber’s article.

There will be a set of ‘default rules’ by which an institution may change the law within its jurisdiction. A rule that makes it harder for the institution to change the law than under its default rules is an ‘entrenching rule’; the rules it makes harder to change are ‘entrenched’.

There are different kinds of entrenchment:

  • Entrenchment by form: the institution must express itself in a certain way to change the entrenched rules.
  • Entrenchment by time: the institution must deliberate for a certain time to change the entrenched rules.
  • Entrenchment by expanded voting unit: there must be more internal agreement, or the agreement of external bodies, for the institution to change the entrenched rules.

There are two reasons for entrenchment of any of these kinds: the promotion of stability and state identity.

There are also reasons favouring some but not all of these kinds of entrenchment. For example:

  • Reminders: It might be a good idea to remind an institution of the reasons against changing certain rules. So we might want to insist that the institution make reference to the opposing arguments before it changes those rules – a kind of entrenchment by form.
  • Moral panics: It might be a good idea to stop an institution from changing certain rules while it’s in the grip of a ‘moral panic’. So we might insist that the institution deliberate for a while before changing those rules – a kind of entrenchment by time.
  • Protecting regions: It might be a good idea to stop a national legislature from bossing around a region on some topic. So we might insist that the region has to agree to changes in the law on that topic – a kind of entrenchment by expanded voting unit.

In some real-life cases, the reasons for entrenchment favour the kind of entrenchment actually adopted (eg, the procedural rules for the Northern Ireland Assembly, the EU Protocol on Subsidiarity). In other cases, the two unfortunately diverge (eg, the Senate filibuster rule). The latter kind of case is a cautionary tale for constitutional drafters.

There’s much more in Barber’s article, and I recommend the whole thing.


There are two ways to depart from an institution’s default rules. The departure could make it harder for the institution to change the law in some area; that’s entrenchment. Or (and now I’m going beyond Barber’s article) the departure could make it easier for the institution to change the law in some area; let’s call that ‘undercut’.

For each kind of entrenchment, there’s a corresponding kind of undercut:

  • Undercut by form: an institution can change the law by expressing itself in a way that wouldn’t be effective under its default rules. Interpretation acts for example, allow legislatures to leave many points implicit, which they would otherwise need to spell out.
  • Undercut by time: an institution can change the law more quickly than it could under its default rules. An obvious example is a ‘fast track’ procedure for the consideration of certain legislative amendments.
  • Undercut by reduced voting unit: an institution needs less internal or external agreement to change the law than under its default rules. It used to be that legislation in Britain needed the approval of the House of Commons, the House of Lords, and the Monarch. By virtue of the Parliament Act 1911, however, only the Commons and the Monarch need to agree to legislation on most topics. (See Jackson v Attorney General for some complications.)

Some of the reasons for undercut are the converse of the reasons for entrenchment. For example:

  • Forgetting to change the law: We worry about law-makers forgetting reasons not to change the law. But they may also forget the reasons to change the law. Thus Britain’s Interpretation Act 1978 says that if the legislature confers a power to make bylaws, it should be taken to confer the power to amend those bylaws.
  • Urgent decisions: We worry about law-makers acting in panic. But we might want the legislature to have a quick legislative procedure to use in times of emergencies or to seize time-limited opportunities (by approving treaties, say).
  • Empowering regions: We worry about national legislatures telling a region what to do. But we could also allow a majority of regional representatives in the national legislature to make law on a matter affecting only their region without needing an overall majority in that legislature. (Something like this idea was under discussion in Britain with respect to legislation affecting only England. The government decided to go in a different direction in the end.)

Law and Convention

Entrenchment can be the result of legal rules or non-legal, conventional rules. This is the difference between ‘legal entrenchment’ and ‘conventional entrenchment’. Barber focuses on legal entrenchment. Fair enough – that’s probably the most common and important kind of entrenchment. When it comes to undercut, though, I think things might be different. ‘Conventional undercut’ seems as common and important as ‘legal undercut’.

In Canada, say, a bill only becomes an Act of Parliament once the Governor General grants royal assent. By convention, though, this assent is not discretionary. The law-making process is facilitated, but not by law. In Britain, the Salisbury Convention tells the House of Lords not to hold up bills that give effect to the government’s election promises. Again, it is a convention that smooths the way for legal change. In Japan, the Cabinet Legislation Bureau has become the forum for interpreting and re-interpreting the Constitution outside of the Supreme Court, which only rarely declares legislation unconstitutional. In these and other cases conventions remove obstacles to legal change.


All of which is to say that I found Barber’s article thought-provoking. If you know of any other examples of undercut, please do tell me. Likewise, I’d be curious to know whether the reasons for entrenchment and undercut are always symmetrical, as in the examples I’ve given, or sometimes asymmetrical. I should confess that I don’t really like the term ‘undercut’. However I can’t think of another antonym for ‘entrenchment’ that works in this context. If anyone else can, I’d be grateful to know

Suggested Citation: Adam Perry, Entrenchment and Undercutting, Int’l J. Const. L. Blog, Nov. 4, 2015, at:


6 responses to “Entrenching and Undercutting”

  1. Adam Tucker Avatar

    Great piece. I think “Henry VIII clauses”, which delegate to the executive the power to amend legislation are a good example of undercutting. You gesture at the HRA version of this (I think) in your mention of “‘fast track’ procedures for the consideration of certain legislative amendments”. The powers created in the The Legislative and Regulatory Reform Act 2006 are another good example.
    I see why you’re dissatisfied with the term “undercut”. But in these examples it is, as it happens, the best term: Henry VIII clauses are just that, a way of undercutting the usual procedures.

  2. Simon Drugda Avatar
    Simon Drugda

    Thank you Prof. Perry for your very interesting piece. Could the controversial Executive (re)interpretation of Article 9 in Japan, provided that other institutional actors accept it, be considered an example of “conventional undercut”?

  3. Simon Drugda Avatar
    Simon Drugda

    I apologize, my question was meant rather, if other institutional actors do not accept it… For example were the Supreme Court to challenge the revision of interpretation of the constitution because it bypasses the formal amendment process.

  4. Adam Perry Avatar
    Adam Perry

    @ Adam – Thanks! Barber distinguishes between entrenchment and jurisdictional limits. For a rule to be entrenched, it has to be within an institution’s jurisdiction. It has to be changeable by that institution through *some* procedure, by using *some* form of words, etc. So, if undercut is the shadow of entrenchment, then giving an institution the power to change a rule in the first place, and thus expanding (or creating) its jurisdiction, isn’t an example of undercut. And, as I understand it, this is what a Henry VIII clause does – grants a power where none existed before.

    Of course we could opt for a different vocabulary, and include jurisdictional changes within ‘entrenchment’ and ‘undercut’. Would that be an improvement? On the one hand the reasons for making it more difficult for an institution to change a rule (stability and so on) seem quite different than the reasons for not trusting the institution with the rule at all (expertise and accountability seem like the main considerations here). On the other hand it’s difficult to keep the categories separate. If an institution can only change a rule if it holds a referendum first, then there’s a sense in which changing the rule is not within the institution’s jurisdiction; it’s not trusted with the rule. But Barber would class the referendum requirement as an entrenching rule.

    So I’m not sure how to class the example. But I think we agree about the reasons against Henry VIII clauses!

    @ Simon – That’s a great question. My first reaction is to say ‘no’. Most conventions are social rules. Social rules depend on acceptance. If people don’t accept that something ought to be done, there’s no social rule requiring it, and thus no convention requiring it. In your example, we have the executive and the judiciary accepting radically different things. Such a deep split at the highest levels would, to my mind, mean that there’s no convention here. But I’m no expert on the Japanese constitution, and it would be intersting to hear from someone who knows more.

    1. Simon Drugda Avatar
      Simon Drugda

      Thank you Prof. Perry.

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