Interim UKIP leader Nigel Farage has warned there will be disturbances on the streets if the British parliament attempts to thwart Brexit.
He said "political anger the likes of which none of us in our lifetimes have ever witnessed" will emerge if voters feel they are going to be "cheated" over the result of June's referendum to leave the EU.
He called on Brexit backers to "get even" via peaceful protests and oppose at the ballot box anyone who seeks to overturn the process.
Doubt has been cast over the British government's plans to trigger the process of leaving the EU by the end of next March after the High Court decided parliament must have the final say.
The judges who ruled Prime Minister Theresa May must seek MPs' approval to invoke Article 50 have been labelled "enemies of the people" in newspaper headlines.
MEP Mr Farage told BBC One's Andrew Marr Show: "We may have seen Bob Geldof and 40,000 people in Parliament Square moaning about Brexit.
"Believe you me, if the people in this country think they're going to be cheated, they're going to be betrayed, then we will see political anger the likes of which none of us in our lifetimes have ever witnessed in this country.
"Those newspaper headlines are reflecting that."
Asked if there will be a real danger of "disturbance in the streets and so on" if Brexit is thwarted by Parliament,
Mr Farage replied: "Yeah I think that's right."
He also reiterated that he is "finished" with party politics, as he sought to downplay any potential return to leading UKIP in future.
Ms May has said she will deliver a full exit from the EU.
Writing in today's Sunday Telegraph newspaper, she said the people had made their choice in June and had done so decisively and it was now the responsibility of government to get on with the job and carry out their instructions.
She also said she is confident of winning a case in the Supreme Court next month arguing against parliament having any say in the triggering of Article 50.
Britain’s health secretary has said parliament will fall into line to back the Brexit process.
Jeremy Hunt also played down speculation that unrest over Brexit will lead to an early general election, insisting it was the "last thing" voters wanted.
It comes after Labour leader Jeremy Corbyn appeared to suggest in a newspaper interview that he would block plans to trigger Article 50 if Prime Minister Theresa May did not guarantee access to single market.
Labour sources later insisted that the party's support for invoking the process was "unconditional" and they would only "seek to amend or influence" the government's negotiating strategy.
Mr Hunt said: "The impact on the economy will be far worse if through some parliamentary mechanism Theresa May is forced to lay out her entire negotiating strategy”.
The government must be given "latitude" to make a deal with the EU, he added.
"For people worried about the impact of Brexit on the economy or whatever else it is, the damage to the fabric of our democracy would be far, far worse if people felt the establishment was trying to unpick a decision that was made," he said.
Mr Corbyn said the UK must have continued access to the single market and there must be no watering down of workers' rights before Labour will back the process.
He is also demanding protections for consumers and the environment and a promise that the cost over lost investment is covered by the government.
He told the Sunday Mirror: "The court has thrown a big spanner in the works by saying Parliament must be consulted. We accept the result of the referendum.
"We are not challenging the referendum. We are not calling for a second referendum. We're calling for market access for British industry to Europe.
"If the Government calls an election we're ready for it," he added.
