The Muslim extremists who threatened disruption at the royal wedding said they have agreed to stay away amid fears they could be targeted for attacks.
Muslims Against Crusades (MAC) announced they have abandoned protest plans as they were heckled by passers-by in an impromptu press conference outside parliament.
Campaign spokesman Abu Abbas, 22, called on all Muslims to stay away on the big day.
"We believe the main issue is security for our people," he said.
One group of onlookers set off a siren in protest at the campaign group, who carried a banner with the words: "Wanted: Prince William … Modern Day Nazi."
Despite threats that Princes William and Harry should "watch their backs" on the campaign group's website, Mr Abbas insisted they had planned only to hold a peaceful protest on Friday.
He said: "We do not want to be caught up with the mayhem. We wanted to be just part of a peaceful protest, to highlight all the oppression and murder.
"But we found out there was a threat of something happening on that day to us. We advise all Muslims to stay away."
Group members, who failed to turn up at a previously arranged meeting with Scotland Yard chiefs, said they would formally withdraw their application to protest.
All groups applying to protest have been told they are likely to be refused permission unless they agree to postpone demonstrations until later in the day.
Assistant Commissioner Lynne Owens, who is leading the major security operation, said MAC had refused the request so did not have an authorised demonstration on the day.
• Billions of people around the world are to watch as Prince William and Kate Middleton tie the knot on Friday - except in one pub, where bosses have banned anything royal-wedding-related.
At the Alexandra Hotel in Derby, the words "royal" and "wedding" are banned, with customers ordered to donate to a "swear box" if they slip up.