The definitive article on left anti-Zionism is here, the online magazine of Progress the independent organisation for Labour party members and trade unionists:
Anti-Zionism is not motivated by anti-semitism. It is motivated by concern for the oppressed. But it nevertheless creates a movement and a worldview that singles out Jews as being a central force for evil and imperialism in the world. Naturally, such movements are beginning to spawn people who are indeed motivated by anti-semitism. And this is where anti-Zionism begins to borrow from older forms of anti-semitism. It insists that Israel’s privileged role as the partner of American imperialism is protected by Jewish influence amongst the neo-conservatives and in American public life more generally. This easily sounds like, and becomes like, the Jewish conspiracy that was the myth at the heart of the ‘protocols’. It still sounds like it, and becomes like it, even if the word ‘Jew’ is replaced by the word ‘Zionist’.
The pro–boycotters have declared their intention to mobilise again in the universities. Some boycotters will be Jewish, some will certainly not be anti-semitic, but they will rely upon anti-semitic justifications. They will find amongst their friends and allies people who hate Israel more than they love Palestine. And they will find amongst their opponents anti-racists who will not tolerate their threat to create an anti-semitic current within the British labour movement.