It defined anti-Zionism as the “belief that the state of Israel has no right to exist” and described its promotion as “politically and morally objectionable”.
Mr Harris, whose successor Nina Freedman is due to take up her role in June, also said motions which do not pass make “no change to UJS policy”.
He added that the union “holds Israel engagement at our very core, being one of our four core values. “
Another motion put forward proposed to recognise the Palestinian people’s "inalienable and collective right" to self-determination.
The proposal, which was passed, cited the union’s repeated support for a two-state solution to the conflict.
“All peoples have the right to self-determination. UJS supports this right for the Jewish people, as with the Palestinian people.
“This is also why UJS was amongst the first major communal organisations to call for a two-state solution, another policy which we adopted and reaffirmed our support for this year," Mr Harris said.
UJS, which passed an anti-BDS motion last year, has led campaigns against the rise of antisemitism and called on UK universities to adopt the International Holocaust Remembrance Alliance definition of anti-Jewish racism.
