Dear Theresa --
I hate to say it, but I told you so! In a blog published here on12 July 2016, I told you that the Brexit referendum result is purely advisory because of the fundamental constitutional principle of the Sovereignty of Parliament. And now a three-judge panel of the High Court has come to the same conclusion, on the basis of which it has ruled that you can't trigger Article 50 to leave the EU without Parliamentary approval.
Parliamentary Sovereignty
The Court's ruling rests squarely on the fundamental constitutional principle of the sovereignty of Parliament. In the words of the Lord Chief Justice for the court: "The most fundamental rule of the UK's constitution is that Parliament is sovereign and can make and unmake any law it chooses."
1,054 Barristers Got it Wrong
This is exactly the point I made in my Huffington Post blog of 12 July 2016 attacking the open letter to David Cameron by 1,054 barristers. My blog was titled: "The Brexit Referendum - Joke letter from 1,054 Barristers." In my blog I made the point that the referendum result is purely advisory: "This is based on a fundamental principle of the British Constitution: the Sovereignty of Parliament." The 1.054 barristers understood the purely advisory nature of the referendum result but gave the wrong explanation for it. Their letter did not even mention the Sovereignty of Parliament. And your government seems to have missed this crucial principle as well.
Your Appeal to the Supreme Court
You seem confident of success in your appeal to the Supreme Court. On what basis? If the Supreme Court decides to reverse the decision just handed down, it will be making a serious error in law. Here (without charge) are all the possible arguments that you could possibly muster in your appeal, together with brief reasons why not one of them has any validity:
•The Government can use the royal prerogative to trigger Article 50. This was your main argument before the High Court. It's wrong because the royal prerogative can't be used to change domestic law, which Brexit would require. And the original 1972 European Communities Act cannot be repealed or amended except by another Act of Parliament.
•The people decided on Brexit in the referendum - so can we not just act on that? No. The UK doesn't have a system of direct democracy but of representative democracy, through Parliament.
•Parliament set up the referendum in the first place, on the understanding that the result would be respected and implemented. The European Referendum Act 2015, passed by Parliament, went into a lot of detail on peripheral matters but did not say what was to happen in the event of a Brexit victory.
•The government gave verbal assurances that the referendum result would be respected and implemented. Maybe so, but without such assurances in the legislation itself, the referendum result is purely advisory - it advises Parliament, which can either accept or reject that advice.
•It's not possible to give an assurance like that in the legislation. Yes it is. The 1979 devolution referenda in Scotland and Wales were preceded by legislation actually establishing devolution in both countries. As neither referendum achieved enough support, that legislation was later repealed.
•If Parliament is sovereign, can't Parliament delegate its power to the people in a referendum? Yes it could, but the only way Parliament could do this is by passing legislation to that effect - which it didn't do on this occasion.
•Parliament has already been consulted on Brexit on numerous occasions. Yes, but it hasn't had the opportunity of voting on it, which is what is required.
•Surely just a quick vote in Parliament is all that is required, not necessarily legislation. No, because of Parliamentary sovereignty, what is needed is actual legislation, passed by the Commons and the Lords and with the royal assent.
•But couldn't Parliament just be asked to say Yes or No to Brexit? No, there will have to be a proper debate on precisely what Brexit means and on how it is to be negotiated, and possibly on the role of the Scottish, Welsh and Northern Ireland governments in the negotiations. Even if Brexit is agreed to, which is probable, there will undoubtedly be some amendments to the government Bill.
•This could create a constitutional crisis. It certainly could, and if your Bill is defeated in Parliament there will probably have to be another general election within a few months. You have no one to blame for this mess but your predecessor and yourself. Why did you not read my blog of 12 July?
Best of luck (you'll need it!)
Dr Michael Arnheim (you can call me Dr Mike)