The Supreme Court has ruled MPs must get a final say on whether Britain leaves the European Union.
Theresa May and her Government had argued ministers alone had the authority to trigger Article 50 – the mechanism for starting the two-year divorce process from Brussels – but judges in the UK's highest court ruled, by eight to three, Parliament must get a vote.
What did the judges say?
The Supreme Court judges ruled, by 8 to 3, that MPs must get a vote on leaving the EU Lord Neuberger, president of the Supreme Court, explained that ministers could not change the law if it impacted on British citizens and their rights.
A majority of judges ruled that, given EU law is currently directly absorbed into UK law when it is made, "a source of UK will be cut-off and, furthermore, the rights enjoyed by British people will be changed" once the UK "withdraws" from the 28-member bloc.
The judges said to ignore that wholesale change would be a "breach of constitutional principle" dating back "many centuries".
"The Supreme Court rules the Government cannot trigger Article 50 without an Act of Parliament authorising it to do so," concluded Lord Neuberger.
So what next?
Attorney General Jeremy Wright, speaking on the steps of the Parliament Square court, said the Government was "disappointed" by the outcome but would "comply" with the judgement.
The next step then will be for the Government to draw up an Act of Parliament for MPs to vote on. The legal bill could be as short as one-line. In their published judgement, which clocks in at more than 100 pages, the judges stated that a "'very brief statute" would suffice.
Given the Prime Minister has signalled her intention to start the exit negotiations by April, a vote is expected in the next two months. A more detailed timeline could be presented by Brexit Secretary David Davis when he makes a statement to MPs in the House of Commons this afternoon.
Labour has already said that, while it will respect the EU referendum result, it will look to make amendments to the Article 50 legislation in order to "prevent the Conservatives using Brexit to turn Britain into a bargain basement tax haven off the coast of Europe".
How will Bristol's MPs and those in the region vote?
Weston-super-Mare MP John Penrose says Parliament must approve Article 50 'pronto'. Conservative MPs, even those who campaigned to remain in the EU, look set to back an Article 50 vote.
Weston-super-Mare MP John Penrose backed staying in the EU but he took to Twitter to announce it was time to get on with kick-starting the process of leaving.
"Supreme Court has spoken on how UK leaves EU," said the former minister. "Now MPs & peers must respect the referendum decision & pass the law which delivers it pronto!"