Gina Miller has called for Boris Johnson to "open the doors" for MPs to return to work on Wednesday after the Supreme Court ruled his decision to prorogue Parliament for five weeks was unlawful.

A panel of 11 justices in the UK's highest court gave their decision on Tuesday in a ruling on the legality of the Prime Minister's advice to the Queen to prorogue Parliament until October 14.

Speaking to reporters outside of the court in Westminster, businesswoman and campaigner Ms Miller, who challenged Mr Johnson's prorogation in the High Court, said the Prime Minister was not above the law.

Supreme Court: Prorogation of parliament was unlawful

"Today is not a win for any individual or cause, it's a win for parliamentary sovereignty, the separation of powers and the independence of our British courts," she said.

"Crucially, today's ruling confirms that we are a nation governed by the rule of law.

"Laws that everyone, even the Prime Minister, is not above.

"Do not let the Government play down the seriousness of the judgment today.

"A unanimous judgment, they have spoken unequivocally."

"And when (sic) I say to the Prime Minister is to repeat Lady Hale's words: the order was a blank piece of paper. Parliament was not prorogued.

"MPs should turn up for work tomorrow and get on with scrutinising this Government.

"We have had twice in three years to come to the Supreme Court, to ensure that the Government does not put itself above the law.

"The ruling today speaks volumes.

"This Prime Minister must open the doors of Parliament tomorrow.

"MPs must get back and be brave and bold in holding this unscrupulous Government to account."