Brexit supporters should be equally concerned to establish at an early stage that Article 50 is exercised in a lawful way. If it is not, it may be of no effect, and raises the possibility of further legal challenges further down the process. Article 50 itself refers to the decision to withdraw being made in accordance with a country's constitution, which suggests that if it is not done properly and lawfully then it is not a valid decision and Article 50 cannot effectively be exercised.

The referendum itself is not sufficient. It is well-established that referenda are not binding, because of the sovereignty of Parliament. Parliament could have made the EU referendum binding when it passed the Act authorising it, but did not. Whether or not the referendum should be binding was not an issue before the High Court, the Government acknowledged it was not, and this will not be an issue for the Supreme Court.

However, the Government is politically committed to accepting the result, because of statements made both before and after the referendum. The legal question now is whether it can do so using prerogative powers. We should all, regardless of political persuasion or our views on any particular issue, be very waryof extending the powers of any government to do whatever it wishes without any oversight.

Legal clarity is essential. If that means getting Parliamentary approval then that is a hoop which must be jumped through. I understand Brexiteers' concerns about this, but if Parliament were to reject Brexit in the face of the referendum there would be an immediate political and constitutional crisis, and very possibly civil unrest. I think it is more likely that Parliament would (perhaps reluctantly) support Brexit, and concentrate on ensuring that we leave in a way which is in the best interests of the country (if we can ever agree what these are)..