The Government will bring a Bill to Parliament to start the legal Brexit process "within days", after the Supreme Court ruled against Theresa May's plans and decreed that MPs were entitled to vote on whether to trigger Article 50.
Sources within the Conservative Party told The Independent legislation could be published by Friday and the initial stages potentially put to a vote by Tuesday or Wednesday next week.
Brexit Secretary Mr Davis told the Commons: "I can announce today that we will shortly introduce legislation allowing the Government to move ahead with invoking Article 50, which starts the formal process of withdrawing the European Union."
The Supreme Court verdict is a blow for the Prime Minister, albeit one she had expected and had prepared for, after she initially wanted to launch the Brexit process unilaterally.
There is now no doubt that Ms May must seek the permission of MPs, a vote due by the end of March, before invoking Article 50 and starting a two-year countdown to Brexit
Delivering the judgement, Supreme Court President Lord Neuberger said: "By a majority of eight to three, the Supreme Court today rules that the Government cannot trigger Article 50 without an Act of Parliament authorising it to do so."
Lord Neuberger said the judgment was not about the referendum result or a comment on the merits of leaving or staying in the EU.
"The referendum is of great political significance, but the Act of Parliament authorising it did not say what would happen afterwards," Lord Neuberger said, meaning any action taken now must be in keeping with the UK’s constitution.
"So any change in the law to give effect to the referendum must be made in the only way permitted by the UK constitution, namely by an Act of Parliament.
"To proceed otherwise would be a breach of settled constitutional principles stretching back many centuries."
The Independent reported today that ministers were likely to be ready to publish the Bill that MPs will vote on by the end of the week.
After the judgement, Attorney General Jeremy Wright said the Government was "disappointed" by the final decision in its historic battle over who has the right to authorise the start of Brexit.
He added: "The Government will comply with the judgement of the court and do all that is necessary to implement it."
A Downing Street spokesman said: "The British people voted to leave the EU, and the Government will deliver on their verdict - triggering Article 50, as planned, by the end of March. Today's ruling does nothing to change that.
"It's important to remember that Parliament backed the referendum by a margin of six to one and has already indicated its support for getting on with the process of exit to the timetable we have set out.
"We respect the Supreme Court's decision, and will set out our next steps to Parliament shortly."
It is unclear what would happen legally if MPs vote against such a bill, as much of the constitutional law related to Brexit remains as yet untested.
Labour leader Jeremy Corbyn has "asked" his MPs to vote not to obstruct it.
The judges' ruling is a victory for Gina Miller, a philanthropist and banker, who brought the case against the Government. She was also backed by a crowd-funded group called The Peoples' Challenge, who described themselves as a group of "concerned EU citizens".
Although the Government lost the challenge, the justices unanimously ruled the Government did not need to consult with the devolved powers in Scotland, Wales and Northern Ireland.
In a statement released immediately after the ruling, Labour leader Jeremy Corbyn said his party would not "frustrate the process for invoking Article 50" but would seek to amend the Government.
Shadow Brexit secretary Sir Keir Starmer said it would be "against the spirit of the judgment" if the Government tried to introduce a one-clause Bill.
He told Sky News: "If it's a simple piece of legislation we would then want to amend it to ensure Parliament does have a proper role and a meaningful role in the process."
The Government must produce a formal Brexit plan so progress can be tested against it, Sir Keir said.
"The vote at the end of the exercise is really important. In other words, Parliament needs to have a meaningful role at the outset in knowing and setting out objectives but also a grip on the process until we get to a conclusion," he added.
The SNP, said it would put forward 50 "serious and substantive" amendment, while the Liberal Democrats will vote against triggering Article 50 unless Ms May promises a second referendum on the final exit deal.
Lord Chancellor Liz Truss, who faced claims she had not spoken out quickly enough in defence of three High Court judges who ruled against the Government on the case last year, delivered a staunch defence of the judiciary following the Supreme Court ruling
In a statement issued minutes after the judgement was handed down, she described the justices as "people of integrity and impartiality".
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