U.K. Supreme Court expected to rule next week on Johnson's suspension of Parliament

British Prime Minister Boris Johnson could suspend Parliament again even if the Supreme Court rules that his original suspension, or prorogation, was unlawful, a court document tweeted by an opposition lawyer showed on Thursday.

The document, submitted to the court by Johnson's lawyers, was disclosed as Britain's top judicial body was hearing a third and final day of legal arguments on whether the prime minister's decision to suspend parliament from Sept. 10 to Oct. 14 was lawful.

At the end of a three-day hearing the court's president, Brenda Hale, said the 11 judges would give their ruling early next week.

On Tuesday, one of Johnson's lawyers had told the court that if the prime minister lost the case, he could recall parliament earlier than scheduled.

This would give more time for legislators to scrutinize and oppose his plans to lead Britain out of the European Union, with or without a divorce deal, on Oct. 31.

But in the new document, not disclosed to media but published by lawyer Jo Maugham — one of those involved in the legal challenge — Johnson's legal team appeared to say there would still be a way for him to keep parliament from sitting, depending on the exact wording of the court's judgment.

"Depending on the court's reasoning it would still either be open or not open to the PM to consider a further prorogation," two senior lawyers representing Johnson said in a written submission to the court.

Johnson's lawyers had been asked by the judges to explain what he would do if it ruled against him. The document tweeted by Maugham was their response, he said.

"The [submissions from Johnson's lawyers] contemplate a world where the Supreme Court rules this prorogation unlawful and the government is plainly contemplating, in that world, continuing the prorogation until October 14," Maugham said on Sky News.

The reason given by Johnson for suspending Parliament for five weeks was that he needed time to prepare a new legislative agenda. His opponents say the real reason he sought the suspension was to prevent Parliament from interfering with his Brexit strategy.

Former PM Major opposing Johnson's bid

Johnson's opponents contend the real reason he sought the suspension was to prevent Parliament from interfering with his Brexit strategy, and therefore he unlawfully misled the sovereign with his advice.

Under the U.K.'s complex, uncodified constitution, Parliament is sovereign, although the exact scope of that sovereignty has been subject to legal debate during the Supreme Court hearing.

Before the suspension, Johnson suffered one defeat after another in Parliament, where he has no majority.

Most members of the House of Commons are opposed to a so-called "no-deal Brexit" scenario, predicting that it would cause economic damage and severe disruption, including to food and medicine supply chains.

Among Johnson's opponents in the Supreme Court hearing is one of his predecessors as prime minister and Conservative Party leader, John Major, who has submitted a written witness statement saying that the evidence showed that the reason given by Johnson for the suspension was not true.

"The inescapable inference to be drawn [from the evidence] is that the prorogation is to prevent Parliament from exercising its right to disagree with the government and legislate as it sees fit," Major said in the witness statement, according to an excerpt read out in court by his lawyer.

The Conservatives are more divided than ever over the EU issue. Using his authority as an elder statesman, Major has said Britain should remain in the EU, and has warned that a no-deal Brexit would be disastrous for the nation.

Britain said on Thursday it had shared documents with Brussels setting out ideas for a Brexit deal, but an EU diplomat described them as a "smokescreen" that would not prevent a disorderly exit on the Oct. 31 divorce date.

Frustration in EU

Ireland said on Thursday Britain had failed to supply credible Brexit proposals and there had been no breakthrough at talks on Wednesday with the Northern Irish party that supports Johnson's Conservative government.

Foreign minister Simon Coveney said frustration was growing in the EU that London had not yet tabled "credible proposals."

France said time to agree a Brexit deal was running out and that Britain needed to come up with something concrete in the coming days if it hoped to clinch an agreement with EU leaders at an Oct. 17-18 summit.

Finnish media cited Prime Minister Antti Rinne as saying that he and French President Emmanuel Macron had agreed an end-September deadline for Johnson to present a concrete proposal to avoid a no-deal Brexit.

"We are a bit worried over what is happening at the moment in Britain and the mess which is created in Europe," Finnish media cited Prime Minister Antti Rinne as saying.

A British government spokesperson pushed back against the idea that a deadline was looming.

"We will table formal written solutions when we are ready, not according to an artificial deadline, and when the EU is clear that it will engage constructively on them as a replacement for the 'backstop'," he said.

British Brexit minister Stephen Barclay said London was in no rush to comply with EU requests for specific written proposals and urged the 27 other member states to be flexible and creative to reach a deal.

"Why risk crystallizing an undesirable result this November when both sides can work together until December 2020?" Barclay said in Madrid. "We risk being trapped in a zero-sum game and that will lead to zero-sum outcomes."

The EU warned on Wednesday that Britain was headed for just such an outcome as London's ideas for solving the contentious issue of how to treat the Irish border were far from unlocking a deal. It said Britain should stop pretending to negotiate

Sitting on one island, Ireland is in the EU but Northern Ireland is part of the United Kingdom, so the border between them will become Britain's frontier with the EU after Brexit.

Opponents of the backstop in the British Parliament worry it would lock the United Kingdom into the EU's orbit for years.