I'm a Labour Party member, have been my whole life, I have seen it first hand in the party. It is often cloaked under anti-Israeli sentiment but it exists. For example, perhaps in someone responding to this question 'There were about 80 MPs in LFI. How many leave before antisemitism is dealt with?' with this response, 'All of them hopefully. Get the Zionists out of the LP. They support an apartheid state.'
I'm not a supporter of the Israeli states actions, and I support the Palestinian people. I do not support cloaking this support in antisemitism. It happen and it needs to be faced up to - even if it is being used by certain sections to beat the Labour party, that doesn't change it exists.