The last few days have seen some notable legal interventions in the Brexit saga.

The "Humble Address" to the Crown, which was approved by the House of Commons on 9th September 2019, in effect  requires the UK Government to produce all documents "to, from or within the present administration, since 23 July 2019 [i.e. the date after which Mr Johnson became Prime Minister] relating to the prorogation of Parliament" sent or received by one or more of a number of named individuals, who are advisers to the current UK Government. The "Humble Address" also requires the production of all documents prepared within Government since 23rd July 2019 "relating to Operation Yellowhammer and submitted to the Cabinet or a Cabinet Committee". All documents will need to be produced to the House of Commons by 11pm UK time on Wednesday 11th September 2019.

The "Humble Address" is an ancient Parliamentary procedure, which appears to rely on a convention that the Crown will exercise its prerogative power to order the production of documents to Parliament following a "Humble Address" by either House of Parliament to the Crown to do so.

The extent to which this "Humble Address" procedure is available is unclear and the "Humble Address" in the present case has been carefully worded as clearly as possible so as not to raise allegations that it is too arbitrary or vague to be capable of implementation.

On 11th September 2019, the Inner House of the Court of Session in Scotland ruled that the Prime Minister's advice to the Crown recommending the extended prorogation of Parliament from a day between 9th and 12th September until 14th October 2019 was unlawful because it had the purpose of "stymying Parliament".

This is in contrast to the ruling of the English High Court the previous day in "Miller v Prime Minister" that the advice was lawful because it "was inherently political in nature" and not the business of the Courts to adjudicate upon.

Both rulings are being appealed to the Supreme Court for hearing on Tuesday 17th September 2019 with the inherent risk that there could be a difference between Scottish and English law, which would be a problem going to very heart of this United Kingdom.

Clearly any documents produced to the House of Commons as a result of the "Humble Address" might contain very relevant evidence of Government intent with regard to prorogation,  which the Supreme Court would wish to consider. The extent, however, to which such documents can be cited in Court or is covered by Parliamentary privilege is, however, unclear.

The United Kingdom is renowned for having one of the most robust and incorruptible legal systems in the World, the envy of less happy lands.

If Brexit achieves nothing else, it has given and will doubtless continue to give ample opportunities for this to be demonstrated.