In less than two months from now, the UK will automatically exit the European Union (EU) on 31 October. The government alone need do nothing to make that happen; and Parliament cannot stop it. But Brexit continues to test political and constitutional boundaries, with real implications for what happens next.
The prorogation of parliament means that it will not sit again until mid-October and, importantly, that all outstanding Bills, including measures intended to address Brexit day-one issues, have fallen and will need to start their parliamentary passage afresh.
It looks highly unlikely that all of the measures that the government considered necessary to provide for the immediate post-Brexit position can now be introduced by 31 October.
The highest court in Scotland has ruled that the prorogation was unlawful and therefore a nullity.
In contrast, in England and Wales, a divisional court concluded that the lawfulness of the prorogation cannot be judicially reviewed.
So, the current position is that the prorogation is lawful and effective in English law, but unlawful and ineffective in Scottish law – both heading to the Supreme Court on appeal.
If the Supreme Court agrees with the Scottish court that the decision to prorogue can in principle be reviewed for lawfulness, then it will have to consider whether it also agrees that, on the evidence (or, rather, the lack of it from the government), the prime minister's dominant purpose was – contrary to the advice he gave the queen – to deny the proper role of Parliament in scrutinising the government.
If it does, then Parliament may return immediately – although it would not in theory preclude the government from then seeking prorogation on a proper basis.
That conclusion would undoubtedly test the boundaries of judicial review of prerogative decisions but, with no hard and fast exclusion from review, the Supreme Court may well determine that it is no more desirable for it to have to draw the line between "high politics" and justiciability than for it to have to adjudicate, as in this case, on the evidence.
That evidence may be augmented in coming days by information published in response to Dominic Grieve's successful motion for a "humble address" requiring the government to publish details of internal communications regarding Operation Yellowhammer and the prorogation decision.
Before Parliament was prorogued, it passed an Opposition Bill requiring the government to seek an extension if it has not by 19 October either reached an agreement with the EU that is acceptable to Parliament or has obtained Parliament's approval to leave without a deal.
While the government has — seemingly reluctantly — confirmed that it will abide by the law, the prime minister has said that he will not seek an extension.
This raises the prospect of his resignation and/or a general election.
The question for the government will be how it can trigger a general election without opposition support, when that support will not be given unless and until the government has obtained a Brexit extension.
Neither of the legal mechanisms for calling an election can be triggered while Parliament is prorogued, as they require a vote of the House of Commons.
And if the UK does ask… it will be up to the EU27 to decide whether to extend again – and they must agree any extension unanimously.
The Supreme Court’s decision could see Parliament return, the prime minister resign, and an election brought forward.
That may or may not affect the Brexit timetable – all is speculation at present.
In the meantime, the default position remains a no-deal departure on 31 October, probably without all of the legislative measures that the government had planned.
Businesses and their advisors must prepare for that outcome.
As the political wrangling continues our advice remains: prepare for the worst, hope for the best.
Many companies developed no-deal contingency plans in advance of the original Brexit deadline, including securing alternative transport routes, stockpiling products and moving licences to holders in the EU27. Those plans should be revisited and updated.
Some companies ran out of time to implement all the actions identified, so now is the time to prioritise what still needs to be done to safeguard business operations as far as possible in the event of a no-deal exit.
