In the space of less than 48 hours, the Government has gone from staring at the prospect of an embarrassing Brexit rebellion and potentially even defeat in a parliamentary division, to securing an official vote by MPs in favour of leaving the European Union, for the first time in the history of the House of Commons. The SNP criticised Labour for handing the Government a “blank cheque” over Brexit. Prominent Tory eurosceptic Iain Duncan Smith celebrated it. Labour’s original motion was deliberately innocuously drafted in order to make it as palatable as possible to potential Tory rebels. The Government would surely have been coming round to the view that it would have been impossible to progress indefinitely without publishing at least a rudimentary outline of its overall Brexit strategy – public opinion would not have permitted that. This has now very much played into the Government’s hands in allowing them to retain a huge amount of flexibility over their Brexit plans, whilst withholding whatever they “reasonably judge to damage” the UK’s prospects in the negotiations. As you were, then. But by calling Labour’s bluff and daring them to vote against accepting the result of the referendum and triggering Article 50 by the end of March next year, the Government has succeeded in securing explicit parliamentary approval for the one crucial step it needs to take that has been so fraught with difficulty up to this point. (It also gave us a number of cracking speeches from the likes of Douglas Carswell, Michael Gove, Jacob Rees-Mogg and Iain Duncan Smith) Yes, the vote is not legally binding in that it is simply a motion, rather than legislation. But it may yet have significant legal consequences – its timing could not have been more ideal for the Government as the Article 50 Supreme Court challenge enters its final day. James Eadie QC, representing the Government, has regularly appeared to be struggling to make any real headway in presenting his case, with the Supreme Court judges frequently disputing his arguments and often seeming unconvinced by many of his points. In contrast, Lord Pannick QC, representing Gina Miller, has largely progressed through his submission with ease, comfortably fielding the vast majority of questions put to him and even sharing in a number of jokes with the judges, so relaxed was the atmosphere at times. Pannick’s central contention – that the Government was not able to use executive proclamation to remove rights which had been granted by statute, namely the European Communities Act 1972 – was largely well-crafted, drawing on a wide range of significant judgments from across centuries past to argue that the Government could not trigger Article 50 legally without prior approval from Parliament. Pannick dismissed the notion that yesterday’s motion had any bearing on the case. But the President of the court, Lord Neuberger, was not so sure. The major issue now confronting the Supreme Court is the principle, at least equally significant in constitutional terms as any of the cases cited by Pannick, that the judiciary is not able to trespass on the business of Parliament by compelling it to pass legislation. This is a very well established principle of the separation of powers and has been repeatedly upheld in numerous judgments (for example in R (Wheeler) v Office of the Prime Minister  – the attempt to force the Government to hold a referendum on the Lisbon Treaty). If the Supreme Court were to rule now that the Government was still unable to trigger Article 50, in spite of the parliamentary motion calling for them to do so, it would effectively be telling Parliament: “what you’ve done isn’t good enough, you need to go and pass a bill instead.” To do so would be to intrude unacceptably on the territory of Parliament. Suddenly it is Pannick’s case that starts to look baroque, rather than the Government’s. There is, after all, no explicit restriction on the Government’s ability to trigger Article 50 laid down in the law, only an implicit one arising from a combination of other legal precedents, at least as argued by Pannick. Amidst the media frenzy surrounding the judges and their possible political leanings and prejudices, it is well remembered that it behoves the judiciary to judge cases purely on issues of law. The idea that the judges are “frustrating the will of the people” may be a valid political point, but it is ultimately a legal irrelevance in itself. The way they have interpreted the law can and should be scrutinised in legal terms, but the judges should rightly not consider factors strictly outside the realm of law. Last night’s amended motion may not be legally binding, but that does not mean it does not have constitutional significance. For were the Supreme Court to demand yet further parliamentary action as a prerequisite for the Government’s action now, they could well be frustrating not just a political imperative, but also a fundamental constitutional, legal imperative – that the judiciary may not trespass on the proceedings of Parliament. As any Remainer will happily tell you – Parliament is sovereign.