THE UK Government is facing its greatest constitutional crisis since the Second World War after three Scottish judges announced yesterday that the suspension of Parliament by Prime Minister Boris Johnson was unlawful.

Scotland’s most senior judge Lord Carloway, Lord Drummond Young and Lord Brodie not only found that the prorogation was unlawful, but issued in the Court of Session what was in effect a stinging rebuke to the PM that places his continuation in the office in doubt – not least because the judgement implies he misled the Queen, Parliament and the public.

While No 10 was holding firm to the line that Parliament would not be recalled at this time, pressure was growing last night for the prorogation to be itself suspended so that Parliament could consider the momentous judgement against the Government. As was always likely to happen, the case brought SNP MP Joanna Cherry QC and 75 politicians and peers supported by Jolyon Maugham QC of the Good Law Project will now go to the UK Supreme Court on Tuesday, September 17, when nine of the most senior judges in Britain will hear the case over three days.

They were named last night as Lady Hale, president of the UKSC, Lord Reed, the Scottish deputy president, Lady Black and Lords Carnwath, Wilson, Kerr, Lloyd-Jones, Sales and Hodge, also a Scot.

With similar cases being heard on appeal from the High Courts in London and Belfast – brought by anti-No Deal campaigners Gina Miller and Raymond McCord respectively – they will all be rolled into one case and it will fall to the nine justices to decide whether prorogation was illegal.

READ MORE: Tories refuse to recall MPs despite Court of Session ruling

The case will centre on Johnson’s motives for prorogation and whether he was trying to evade parliamentary scrutiny of Brexit. If the Supreme Court decides that was his real motivation, it is difficult to see how they could find prorogation to be lawful, which in turn would surely end Johnson’s time as PM – either by resignation or a no-confidence vote.

There are potentially more hammer blows coming for Johnson. The decision in the Northern Irish case on whether a No-Deal Brexit breaches the Good Friday Agreement will be announced today, and the full judgement in the Cherry Case, as it has become known, will be issued tomorrow. The National understands that when it is published tomorrow, the full judgement of the three judges of the Inner House of the Court of Session is likely to be even more damning than what has so far been released.

In the original judgement issued last week, Lord Doherty said that prorogation was a matter of politics and not an issue for the courts, with Johnson answerable only to Parliament for his advice to the Queen. The three appeal court judges thought otherwise. Lord Drummond Young said that the UK Government had failed to show a valid reason for the prorogation, adding: “The circumstances, particularly the length of the prorogation, showed that the purpose was to prevent such scrutiny. The only inference that could be drawn was that the UK Government and the Prime Minister wished to restrict Parliament.”

Lord Brodie commented: “This was an egregious case of a clear failure to comply with generally accepted standards of behaviour of public authorities.

“It was to be inferred that the principal reasons for the prorogation were to prevent or impede Parliament holding the executive to account and legislating with regard to Brexit, and to allow the executive to pursue a policy of a No-Deal Brexit without further parliamentary interference.”

SNP MP Cherry said it was a great day for Scots law and added: “We feel utterly vindicated and I would feel confident that the UK Supreme Court will uphold this decision.

“As time has gone on we have uncovered more evidence that this was a plot by Boris Johnson, Jacob Rees-Mogg and others to prevent us representing our constituents’ views and prevent us scrutinising them as they try to take us through a back door towards a No-Deal Brexit.”

A UK Government spokesperson said: “We are disappointed by today’s decision and will appeal to the UK Supreme Court. The UK Government needs to bring forward a strong domestic legislative agenda. Proroguing Parliament is the legal and necessary way of delivering this.”