The result of the Brexit referendum on EU membership has no binding force in law. This was the main point made in an open letter to David Cameron signed by 1054 barristers on 9 July 2016. This is undoubtedly correct. But the rest of the letter, and especially the part that proposes "a way forward", reads like a joke.
Purely Advisory
Let's start with the good part of the letter, which claims that the referendum result is not legally binding but is purely advisory. Quite right. This is based on a fundamental principle of the British Constitution: the sovereignty of Parliament - which, however, the letter doesn't even mention!
Delegation of Power
But, as Parliament is sovereign, can't Parliament delegate powers to other bodies? Yes, it can. So, can Parliament delegate power to the electorate to decide an issue by means of a referendum? Yes, it can. The trouble is that Parliament can only delegate power by passing legislation to that effect - and no such legislation was passed in regard to the Brexit referendum. The legislation arranging the referendum, called the European Referendum Act 2015, goes into a huge amount of detail about all sorts of technical matters, but there is nothing at all about the legal status of the referendum result nor any indication of what would happen in the event of a Brexit vote.
The 1975 EC Referendum
The UK joined the European Community (EC) without a referendum in 1973. Harold Wilson's Labour Government held a referendum in 1975 on whether the country should remain in the EC or leave - the same question as in this year's referendum. But, unlike now, the Wilson Government made it clear that, though the referendum result did not bind Parliament, the Government would honour it, which of course they did.
Wrong End of Stick
The 1054 barristers' letter gets hold of the wrong end of the stick. Instead of basing the advisory nature of the referendum on the bedrock constitutional principle of Parliamentary sovereignty - which is the true basis for it -- the 1054 barristers' letter links this status to the absence of a threshold to leave the EU. It is true that setting a threshold can be a useful device, but it's strictly irrelevant to legal status.
Threshold
The 1979 Scottish and Welsh devolution referendums did have a threshold. Legislation was passed before the referendum introducing devolution. There was a stipulation that for devolution to occur, those voting Yes had to amount not only to at least 50% of those voting but also at least 40% of those entitled to vote. In the Scottish referendum there was a 51.6% Yes vote, which however represented only 32.9% of registered voters. So the legislation introducing devolution had to be repealed. Devolution came only in 1997, this time with a pre-legislative referendum without a threshold.
Royal Commission
The 1054 barristers' letter "proposes that the Government establishes, as a matter of urgency, a Royal Commission or an equivalent independent body to receive evidence and report, within a short, fixed timescale, on the benefits, costs and risks of triggering Article 50 to the UK as a whole, and to all of its constituent populations". The letter proposes that there should then be a free vote in Parliament --- after the" commission" has reported.
Joke?
Is this a joke? Instead of delegating power to the people, what this proposal amounts to is delegating it to a faceless "commission". Secondly, the alternatives identified by the "commission" will not all be automatically available. And they will need years of negotiation. Even the extremely limited agreement between the EU and Canada took seven years to negotiate - and is still not in force! How long, in any event, will it take for the "commission" to produce its report, even on "a short, fixed timescale"? Royal commissions and the like normally take at least four years to report - and the Chilcot report on the Iraq War took seven years.
Practical Solution
The Europe Directorate of the Foreign Office actually produced a surprisingly good report published in March 2016, titled "Alternatives to membership: possible models for the UK outside the EU". After examining the alternative models in some detail, this report concludes, no doubt correctly: "It is the assessment of the UK Government that no existing model outside the EU comes close to providing the same balance of advantages and influence that we get from the UK's current special status inside the EU." However, after failing to tackle the real immigration problem - migration from outside the EU -- and after running a lacklustre campaign, the Government, not surprisingly, failed to persuade enough voters to "Remain". Can they now throw the decision to Parliament on a free vote? Legally, yes, but in practice they must bite the bullet and make the best of a very bad situation. Refusing to guarantee the rights of existing EU nationals in the face of a near-unanimous vote in the House of Commons (on 6 July 2016) is only another example of the Government's general failure.