The rationale is quite straightforward in the sense that, in seeking to achieve maximum certainty, there is danger in allowing the system to create a situation in which the law might rapidly degrade in a way that does not achieve such stability and certainty. I accept it is almost reverse logic, but there is logic in trying to make sure that we have an identifiable and pretty understandable body of retained EU law. I give the example of the EU principle of good administration, which will not have any relevance to our UK law after exit because, of course, the bodies vested in EU agencies will be returned here and all the normal domestic rules about the exercise of such powers by public bodies will apply. Another example is the principle of subsidiarity, which does not make sense outside the concept of EU membership. Secondly, the Bill will, of course, take a snapshot of the law as it stands at the moment we leave. Retaining a right of action based on general principles of EU law, which will of course change in the future, would lead to uncertainty for businesses and individuals about their rights and obligations if we end up in a situation where pre-exit legislation could be struck down, or where administrative decisions could be challenged, on the basis of those principles. In other words, that is an echo of what I was just saying to my right hon. and learned Friend. This is particularly the case given the uncertainty about the way in which principles could develop or about the circumstances in which they would apply after exit. It would make no sense to bind ourselves to such an imprecise, open-ended and uncertain set of principles-it does not mitigate legal uncertainty, but increases it. It makes no sense, once we are no longer an EU member state, to bind ourselves to a set of principles that are the EU's judge-made constitutional principles, when we have our own constitutional and common-law principles. Such an approach risks duplication and confusion. Perhaps more fundamentally, outside the context of EU law, the ability for courts to disapply primary legislation is just inconsistent with the way our constitution works and the balance of powers that has to exist between the legislative and judicial branches.