WESTMINSTER may remain suspended even if Boris Johnson loses a historic legal battle at the Supreme Court, the UK Government has said.

Documents submitted to the court on the Prime Minister’s behalf outline three possible scenarios if his advice to the Queen to prorogue Parliament for five weeks is ruled unlawful.

Two raise the possibility of Mr Johnson simply suspending Parliament again.

A full panel of 11 justices at the UK Supreme Court will give a definitive ruling on whether Mr Johnson exceeded his powers next week.

READ MORE: Universities hit by brain drain as no-deal looms

It follows a three-day hearing arising out of separate legal challenges in England and Scotland, in which leading judges reached different conclusions.

While the High Court said the issue was a political matter, Scotland’s Court of Session ruled the prorogation was unlawful as it sought to “stymie” scrutiny of Brexit.

Yesterday, Supreme Court president Lady Hale stressed the case “is not about when and on what terms the United Kingdom leaves the European Union”.

She added: “The result of this case will not determine that. We are solely concerned with the lawfulness of the Prime Minister’s decision to advise Her Majesty to prorogue Parliament on the dates in question.”

It came as lawyers for former Tory prime minister Sir John Major made an extraordinary intervention to urge the court to rule against the UK Government.

In a written submission, Sir John’s legal team rejected the High Court’s conclusion that it was not a matter for the courts.

They said: “If that conclusion were correct, the consequence would be that there is nothing in law to prevent a prime minister from proroguing Parliament in any circumstances or for any reason.”

They argued this would mean the courts could not intervene even if a prime minister “philosophically opposed to the idea of a standing army prorogued Parliament during the period leading up to the statutory expiry of the relevant Armed Forces Act, with the result that the Act expired and the armed forces were required to disband”.

However, Lord Keen QC, representing the UK Government, insisted the court should not interfere. He said: “This is forbidden territory. It is a matter between the executive and the Parliament.”

Lord Pannick QC, who is acting for Gina Miller, the anti-Brexit campaigner behind the High Court bid, said Mr Johnson’s motive was to “silence” Parliament.

He suggested the court should encourage “the Prime Minister to ensure that Parliament meets as soon as possible next week”.

But documents submitted on behalf of Mr Johnson suggest Westminster could simply be suspended again, even if the original move is ruled unlawful.

They outline three possible scenarios if the court rules against the Prime Minister, two of which could see him make a fresh decision to prorogue Parliament. The other outcome could see the court order Parliament to be recalled, but Mr Johnson’s lawyers urged the judges to consider the “very serious practical consequences” involved in this option, as it would require a new Queen’s Speech and State Opening of Parliament.

READ MORE: SNP launch review into schools after concerns over subject choice

Asked shortly after the hearing ended to rule out proroguing Parliament for a second time, Mr Johnson said: “I have the greatest respect for the judiciary in this country.

“The best thing I can say at the moment whilst their deliberations are continuing is that obviously I agree very much with the Master of the Rolls and the Lord Chief Justice and others who found in our favour the other day.”

He added: “I will wait to see what transpires.”

The Prime Minister advised the Queen on August 28 to prorogue Parliament for five weeks and it was suspended on September 9. Mr Johnson says the move is to allow the Government to set out a new legislative agenda in a Queen’s Speech.