LONDON (AFP) - Prime Minister Theresa May was urged on Saturday (Nov 5) to try to quell the furore sparked by a High Court ruling that she needs parliamentary approval before triggering Britain's exit from the EU.

Former ministers called on her to address the angry backlash after three senior judges upheld a challenge to her right to start the departure process without MPs having their say first.

Mrs May spent Friday (Nov 4) trying to assure European leaders that Thursday's (Nov 3) verdict would not affect her timetable for triggering Article 50, the formal procedure for leaving the European Union.

But on the domestic front, members of her governing centre-right Conservative Party and pro-Brexit newspapers were raging about the ruling, fearing it could derail the process.

Mr Bob Neill, the chairman of parliament's scrutiny committee on justice affairs, said the attacks were "threatening the independence of our judiciary", as he urged Mrs May to intervene.

"Some of the things which have been said about the court's judgment by politicians have been utterly disgraceful," the Conservative told The Times newspaper.

Mrs May and her government "must now make clear that the independence of the judiciary is fundamental to our democracy. You have to respect that even if you think they have got a decision wrong", he said.

Ex-minister Anna Soubry, a prominent Remain campaigner, told The Guardian newspaper that some media coverage was "inciting hatred".

"What message are we sending out to the rest of the world? Probably that this nation is in grave danger of losing the plot - and I think we might have done."

The Daily Mail, which branded the judges "enemies of the people", said on Saturday it was an "anti-democratic ruling", as other newspapers kept up the heat.

Opposition Labour leader Jeremy Corbyn was expected to call on Mrs May to set out her Brexit negotiating strategy in parliament "without delay" in the wake of the High Court ruling.

"There must be transparency and accountability to Parliament about the government's plans," he was to say to a think tank in London on Saturday, according to pre-released extracts of the speech.

"I suspect the government opposes democratic scrutiny of its plans because - frankly - there aren't any plans, beyond the hollow rhetoric of 'Brexit means Brexit.'"

On Friday, Mrs May telephoned European Commission President Jean-Claude Juncker, European Council President Donald Tusk, German Chancellor Angela Merkel and French President Francois Hollande.

She told them the government still intended to invoke Article 50 between the New Year and the end of March, and that she was confident of winning a Supreme Court appeal against Thursday's ruling.

The High Court decision raises the prospect of a protracted parliamentary debate, although EU leaders have urged a swift departure.

In a sign of the likely parliamentary storms ahead, pro-Brexit Conservative lawmaker Stephen Phillips resigned as an MP on Friday, citing "irreconcilable policy differences with the current government".

He said "quitter" was a label he could live with, but "Conservative no longer is".

The resignation leaves Mrs May's government with a slim working majority of 14 in the 650-member House of Commons.

It also fuelled speculation of an early general election, though Downing Street maintains that polls should not be brought forward from 2020.

The Daily Telegraph newspaper reported on Saturday that ministers were openly discussing the possibility.

It quoted an unnamed government member as saying: "The problem we have got is we have a Brexit majority in the country and a Remain majority in Parliament."

"Given this court judgement and the likelihood that we won't win the appeal... I am now open-minded to an early election as many colleagues are."

The pound - which has tumbled to multi-year lows since the referendum - soared against the dollar and euro, standing at US$1.25 during afternoon trading in London on Friday.

Meanwhile, the White House urged Britain and the EU to "continue to be flexible and work this out in a process that is smooth, pragmatic, transparent and productive" following the court ruling.