The legal problems arising from the EU referendum need to be distinguished from the political ones. One thing is clear: the referendum itself had no more legal effect – either within the United Kingdom or on the UK’s legal relations with the European Union – than a straw poll of your friends (or mine). The UK is still a member of the EU and has not, legally, indicated its desire to leave the Union. The political consequences are quite another matter, and may well lead to exit from the EU.

The UK could, in theory, unilaterally withdraw. This would be a radical way to proceed – it would be a repudiation of the UK’s international obligations – and virtually no one endorses it. Before the Treaty of Lisbon, there was no clause dealing with how to withdraw from the Union; now there is, in Article 50 of that treaty. Once invoked, a two-year deadline is imposed on negotiations (though this may be extended by unanimous consent). When the clock starts ticking, the UK’s negotiating position is much worse than the EU’s. Before the vote, David Cameron suggested he would invoke Article 50 immediately; he now says he will leave it to his successor.

Were Article 50 invoked today, a complete agreement would almost certainly be impossible in the two-year timeframe: it took 10 years to negotiate Switzerland’s agreement with the EU. There was hope in some quarters that an agreement could be worked out before Article 50 is triggered. The EU leaders have rejected this possibility. The gridlock can be broken only if one side budges. Neither looks likely to do so any time soon. David Allen Green has suggested in the Financial Times that Article 50 may never be invoked.

The legal and political positions now get harder to cleave. No one knows who has the legal power to invoke Article 50. Some people, including a former government lawyer, believe that the government can invoke the article on its own; others, including constitutional law experts at Oxford and UCL, believe that it cannot be invoked without an empowering act of Parliament. The question of who is right could come to court. But as H.L.A. Hart wrote in The Concept of Law, ‘when courts settle previously unenvisaged questions concerning the most fundamental constitutional rules … all that succeeds is success.’ He meant that, in these rare cases, a court’s decision only changes the law if people accept that it does. Part of the reason it is uncomfortable for lawyers to adjudicate on very controversial political questions is that their success is never guaranteed.

Some questions, Hart adds, ‘may divide society too fundamentally to permit of [their] disposition by a judicial decision.’ A political solution avoids any possibility of dissent from the courts. Yet it may also be hard to come by. A vote in the House of Commons to trigger Article 50 would require many MPs to vote against their conscience on membership of the EU. There would be other arguments of principle: Scottish MPs, for example, could say that they have a democratic mandate to prevent their constituents being withdrawn from the EU against their expressed will.

There are two slivers of silver lining. Were a court to say that an act of Parliament is required, a national court, not a European one, would have resolved the issue. Were an act not forthcoming, that decision would itself affirm the sovereignty of Parliament. This probably wouldn’t dispel the clouds, though that in itself would be telling.