Brexit case goes before Supreme Court in London
All the parties involved in the Supreme Court battle over Brexit have formally given their backing to the 11 justices hearing the historic case, it was announced at the start of the hearing.
The highest court in the land is being asked by government ministers to overturn a High Court ruling that the Prime Minister must seek MPs' approval to trigger the process of taking Britain out of the European Union.
Lord Neuberger, the court's president, said all parties had been asked whether they wished any of the judges to stand down.
He said that all parties to the appeal had stated that they have no objection to any of the justices sitting on the appeal.
The announcement follows media reports and comments that have questioned the independence of members of the judiciary.
Lord Neuberger also said individual members of the public in the case had received "threats of serious violence and unpleasant abuse in emails and other electronic communications" and warned those responsible that "legal powers" existed to deal with them.
In a decision on November 3 that infuriated Brexiteers, three High Court judges said British Prime Minister Theresa May lacked power to use the royal prerogative to trigger Article 50 of the Lisbon Treaty and start the two-year process of negotiating Brexit without the prior authority of Parliament.
Now the 11 Supreme Court justices - a record number to sit on an appeal - will have their say regarding one of the most important constitutional cases in British legal history.
Lord Neuberger is leading a panel including Lady Hale, Lord Mance, Lord Kerr, Lord Clarke, Lord Wilson, Lord Sumption, Lord Reed, Lord Carnwath, Lord Hughes and Lord Hodge.
The hearing will be the most televised UK case ever, with the proceedings streamed on the Supreme Court website and broadcast on television.
In his opening remarks, Lord Neuberger stressed the court was aware of the "strong feelings associated with the many wider political questions surrounding the United Kingdom's departure from the European Union" - but those questions were not the subject of the appeal.
He said: "This appeal is concerned with legal issues and, as judges, our duty is to consider those issues impartially, and to decide the case according to the law. That is what we shall do."
Attorney General Jeremy Wright told the justices that the case was of "great constitutional significance in which there is understandable and legitimate interest both inside and outside this courtroom".
"Secondly, in the light of what followed the Divisional Court (High Court) judgment, it should be said with clarity this is a case which the claimants brought perfectly properly and which it is now perfectly proper for this court to decide."
Mr Wright said the High Court had reached the "wrong" decision.
It was for the British government to exercise prerogative powers in the conduct of the UK's affairs on the international plane.
He told the judges that triggering Article 50 "will not be an exercise of the prerogative right on a whim or out of the blue" but was part of a process in which "Parliament has been fully and consciously involved".