LONDON (BLOOMBERG) - Boris Johnson's suspension of Parliament reaches the United Kingdom's top judges this week, forcing them into the political arena on an issue that has divided the courts and the country.

The UK Supreme Court, located just yards from the Palace of Westminster, cut short its summer break to take a case that will decide whether the Prime Minister must let lawmakers return.

The 11 judges are convening to rule on an issue that pits the judiciary against the government and an English ruling against one from Scotland.

At the centre of the debate is whether the decision to suspend Parliament in the countdown to an Oct 31 Brexit deadline is even a matter for the courts.

Senior judges in Edinburgh decided it is, agreeing with a group of lawmakers that the prorogation's purpose was to stymie Parliament and was thus unlawful.

That's a completely different conclusion to their counterparts in London.

"It is High Noon for the decision on the lawfulness of the government's prorogation," said Mr David Mundy, a lawyer at BDB Pitmans who advises lawmakers on introducing Bills.

"With the Scottish court taking a contrary view, the constitutional stakes could not be higher."

The Scottish ruling was a blow to Mr Johnson, who suffered several heavy legislative defeats in Westminster before Parliament was shut.

He is argued that a new law forcing him to seek an extension for the UK to remain in the European Union has hurt his negotiating tactics.

Mr Johnson has resisted asking EU officials for more time, and is now calling for a domestic election.

In their decision, the Scotland appellate judges, called the Inner House of the Court of Session, rejected Mr Johnson's framing of the suspension as a chance to put forward a new political agenda.

"This was an egregious case of a clear failure to comply with generally accepted standards of behaviour of public authorities," Judge Philip Brodie said in the ruling.

It is only the second occasion that 11 judges will meet as a full bench at the Supreme Court. The same number decided an earlier case brought by Ms Gina Miller, a businesswoman who successfully challenged Mr Johnson's predecessor Mrs Theresa May's reluctance to allow parliamentary scrutiny of a key Brexit withdrawal Bill.

Ms Miller is back with her old legal team, calling the suspension an abuse of power.

This is the first time that prorogation has been subjected to a legal challenge. Mr Johnson argues that the suspension is just a normal power exercised by government ministers in their advice to Queen Elizabeth II.

"We are in uncharted legal waters dealing with an extremely novel constitutional question and the legal argument is all quite creative, so different judges come to different conclusions about the answer," said Mr Raphael Hogarth, an associate at the Institute for Government, a London research group.

"The question you are asking in the round is: Is there a good reason for the court to intervene?" he said.

The judges in England said that there wasn't. Even if Parliament was prorogued to "advance the government's political agenda" on Brexit, "that is not territory in which a court can enter", the judges led by Mr Ian Burnett, the Lord Chief Justice, said in their decision.

The length of the prorogation - an unprecedented five weeks - attracted considerable scrutiny, but the English court also said it didn't have the tools to decide if it was too long.

"It is impossible for the court to assess by any measurable standard how much time is required 'to hold the government to account'," the English judges said.

Whatever the result, Mr Johnson has said he will abide by the decision, after some ministers had appeared to cast doubt on the impartiality of Scottish judges. That harked back to tabloid headlines that said judges who backed Ms Miller's position in the earlier Brexit hearing were "enemies of the people".

"The courts are dealing with questions of political significance that we'd normally expect to see dealt with in Westminster and that's because the executive is suggesting it might act in a very unusual way itself," Mr Hogarth said.