Theresa May is moving to restore her grip on Brexit as calls mount for an emergency general election to settle the question of British withdrawal from the EU.
The Prime Minister was engaging in an urgent round of telephone diplomacy in the wake of the High Court decision which insisted Parliament must have the final say on Britain triggering divorce deal negotiations with Brussels.
Mrs May is calling European Commission president Jean-Claude Juncker on Friday in a bid to try to persuade continental leaders that the explosive legal ruling would not shake her from the pledge to invoke Article 50 of the Lisbon Treaty - which would formally launch Brexit - by April next year.
But the uncertainty created by the High Court judgment was underlined by Tory former chancellor and ardent pro-European Ken Clarke, who told BBC Newsnight he would move to block invoking Article 50, saying: "I will vote against it. I shall stick to my guns. I will not cast a hypocritical vote."
With the largely pro-EU Commons in the Brexit driving seat pending an appeal of the High Court ruling to the Supreme Court in early December, interim Ukip leader Nigel Farage called on Mrs May to call a snap general election, even though he said such a move would face stiff opposition from Tory and Labour benches alike.
Writing in the Daily Telegraph, Mr Farage said: "The best thing Theresa May could do now would be to call a general election, but 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.
"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."
After the High Court ruling rocked Westminster, Brexit Secretary David Davis conceded that an act of Parliament would now be needed to trigger Article 50, with Mrs May's spokeswoman stating his view was the "logical conclusion" to draw from the High Court judgment.
The spokeswoman said Mrs May was keen to tell other European leaders she would stick to the declared timetable for withdrawal, stating: "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 judgment is not going to derail that."
Shadow foreign secretary Emily Thornberry told the BBC: "I think that Article 50 is going to happen. I think that in the end Parliament will vote for Article 50 to be triggered. But the really good thing about this judgment ... is that the Government will need now to come to Parliament and actually give us some basic terms on which they are going to negotiate Brexit. We do not allow the executive a free hand."
Mr Juncker's spokesman made it clear to reporters in Brussels that the phone call was taking place at the request of the Prime Minister, not Brussels.