THE Attorney General reportedly told the Prime Minister it was lawful to suspend Parliament – advice that 11 of the UK's top judges have since savaged in a landmark ruling.

Sky News published a leaked document revealing part of the text which was redacted when released by the Supreme Court.

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It shows that Geoffrey Cox told Cabinet that Boris Johnson's advice to the Queen on prorogation was "lawful and within the constitution".

The QC is also said to have told the Tory Party leader that any criticism of such a move would be politically motivated.

Following a meeting with Commons Leader Jacob Rees-Mogg and Number 10 aide Nikki da Costa at Balmoral last month, the Monarch prorogued Parliament for five weeks, with the Commons doors shut for business until October 14.

Yet all 11 Supreme Court judges ruled that the instructions were "unlawful" and confirmed the suspension no longer stood.

Cox, according to the unredacted version of court papers released to lawyers challenging Parliament's suspension, is said to have assured Cabinet that the decision to prorogue would not be overturned.

"The attorney general said that his advice on the question of the law is that this was lawful and within the constitution," the papers revealed.

"Any accusations of unlawfulness or constitutional outrage were motivated by political considerations."

But judges unanimously ruled that the advice given to the Monarch was "unlawful, void and of no effect".

The Supreme Court's decision directly contradicts Cox's legal opinion, a situation that could put pressure on the senior Tory following the leaking of his advice.

Lady Brenda Hale, announcing the judgment, said: "The court is bound to conclude that the decision to advise Her Majesty to prorogue was unlawful because it had the effect of frustrating or preventing the ability of parliament to carry out its constitutional functions."

Keir Starmer, Labour's shadow Brexit secretary, is planning to enact a seldom used Commons procedure to force the Government to release its legal advice on prorogation.

Former Conservative MP Amber Rudd, who quit as work and pensions secretary earlier this month over the PM's Brexit handling, said Cabinet ministers requested to see such papers but they were not handed over.

"Despite personal assurances from the PM, the Cabinet was not shown the legal advice around this prorogation," she tweeted.

Northern Ireland Secretary Julian Smith is also understood to have pushed to see detailed legal assessments.

Johnson, who is due to fly back early to the UK from the United Nations General Assembly meeting in New York, told reporters he did not think the judges had come to the "right decision".