British Prime Minister Theresa May is attempting to take back control of Brexit, after the UK High Court ruled she needs the support of MPs before starting negotiations to leave the European Union.
She will speak to European Commission president Jean Claude Juncker today to reassure him she still intends to trigger Article 50 by the end of March.
Meanwhile, acting UKIP leader Nigel Farage has added his voice to calls for Mrs May to call an emergency general election following the legal setback.
He said she should go to the country even though such a move would be strongly opposed by Tory and Labour MPs alike.
Writing in the UK's Daily Telegraph, Mr Farage said: "It is unlikely that Labour MPs, led by a man they don't believe in, would be keen on facing the likely electoral oblivion that would follow.
"It also seems likely that some on the Prime Minister's own backbenches, who are seeking to overrule the will of the British people, would be unlikely to support an early general election either."
He went on: "The establishment, in denial after the referendum result, still just don't get it.
"The British people are not simply going to let this incredible establishment arrogance lie. I suspect even more radical political change is on the way."
The UK government immediately announced it will appeal against the ruling and take the matter to the British Supreme Court in early December.
"Sticking to the timetable"
A Downing Street spokeswoman said Mrs May was keen to tell other European leaders she would stick to the declared timetable for withdrawal.
She added: "She will set out what the process is, which is that we are appealing and that we are carrying ahead and sticking to the timetable we have set out.
"This judgement is not going to derail that."
Gina Miller, the businesswoman who brought the case with hairdresser Deir Dos Santos, welcomed the outcome, saying it would "bring sobriety" to Brexit proceedings.
In a statement, Mr Dos Santos said: "In her speech to the Conservative Party Conference the Prime Minister attacked me for bringing these proceedings as a claimant.
"She said that I was trying to subvert democracy. That was an unwarranted and irresponsible attack.
"As is my constitutional right, I sought the protection of the court to stop unlawful government action. The court has now given me that protection."
Opposition leaders Nicola Sturgeon, Tim Farron and Jeremy Corbyn, who have been calling for Mrs May to lay out her Brexit strategy more clearly, also welcomed the ruling.
Labour leader Mr Corbyn said: "(It) underlines the need for the Government to bring its negotiating terms to Parliament without delay.
"Labour respects the decision of the British people to leave the European Union. But there must be transparency and accountability to parliament on the terms of Brexit."
Ms Sturgeon said Scotland could join the Brexit court battle to make sure Mrs May does not win back the power to trigger Article 50.
"We'll be looking at the judgement very carefully and yes we will actively consider whether or not there is a case for the Scottish government to become participants in that case," she told the Scottish Parliament.
