Britain's former chief rabbi has warned that Jewish people are thinking about leaving the country because of anti-Semitism.
Jonathan Sacks told the BBC on Sunday that for the first time in the 362 years Jews have been in Britain many question whether it is safe to raise children here.
He singled out Labour Party leader Jeremy Corbyn for failing to address anti-Semitic attitudes in the main opposition party, saying Corbyn would pose a danger as prime minister unless he expresses "clear remorse" for past statements.
Sacks said "when people hear the kind of language that has been coming out of Labour, that's been brought to the surface among Jeremy Corbyn's earlier speeches, they cannot but feel an existential threat."
Gordon Brown, the most recent Labour Party leader to serve as prime minister, added his voice to the chorus of party figures calling for Labour to endorse an internationally agreed-upon definition of anti-Semitism rather than the more limited one now in place.
He told the Jewish Labour Movement conference the change should be made immediately.
"It is needed now to deal with practical threats, to confront gathering dangers and on-the-ground realities of very real, week-by-week threats to Jewish communities that demand an unequivocal response and unqualified resolve," he said.
The party's executive committee is set to discuss its definition of anti-Semitism in the coming days.
Corbyn has said anti-Semitism has no place in the Labour Party.