Labour has "let the Jewish community down" over its handling of anti-Semitism within the party, according to Gordon Brown.
In a video published by anti-Racism charity Hope Not Hate on Monday, Mr Brown said the party had been too slow in dealing with cases of anti-Semitism.
Mr Brown also paid tribute to the late Sir Nicholas Winton, who joined the Labour Party in 1936 and who organised the rescue of 669 Jewish children from Nazi-occupied Czechoslovakia on the eve of the Second World War before helping them to begin new lives in Britain.
Mr Brown said: "The Labour Party has always had a long, proud and noble tradition of standing up against all forms of prejudice and racism.
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"But in the last few years it has let the Jewish community down.
"They should never have allowed legitimate criticism of the current Israeli government to act as a cover for the demonisation of the entire Jewish people."
The former prime minister made the comments as he announced he has joined the Jewish Labour Movement as an affiliated member.
Mr Brown added: "The message to the Jewish community should be clear and unequivocal: 'You will never walk alone and we will never walk on by on the other side. We must never tolerate intolerance.
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"Solidarity means standing up with those who are under attack and that is why I am joining as an affiliated member. I urge all my colleagues to do the same.
"Tackling anti-Semitism and racism and fighting for equality is not a diversion nor a distraction from our purpose as party - it is our purpose as a party.
"We will never allow evil to triumph over good and neither will the British people."
