Former Norwood president Richard Desmond has called on the community to "stand up and fight" against rising antisemitism, and not "bury their heads in the sand".
The billionaire media tycoon said the anti-Jewish hatred during last summer's Gaza conflict, when Norwood charity shops were daubed with antisemitic graffiti, was the worst he had ever seen.
"That was terrible and really shocked me," he said. "I just didn't expect that it would happen here. I realised then how important it is to speak out in support of Israel.
"We can't bury our heads in the sand or whisper about people who are against Israel or who hate Jews. You have to stand up and fight."
Mr Desmond said he had previously wondered whether the community felt "too comfortable", with people believing no serious threats would emerge in Britain.
"In America they are much more aggressive - I'm not saying we need to be like that but we do need to show that we won't be intimidated," he added.