Lincoln, Newcastle and Hull student unions have voted to split from the NUS, while decisions from the respective bodies at Loughborough, Nottingham and York are still to come.
The Oxford result was announced after a week in which it was revealed that Ms Bouattia was found guilty of misconduct by the NUS last year over alleged antisemitic comments.
It then emerged that the Union of Jewish Students was aware of the investigation at the time, but chose not to release this information when Ms Bouattia ran for president.
Ms Bouattia has attracted criticism for comments made ahead of her election. She described Birmingham University, which has a large Jewish student population, as a “Zionist outpost” and referred to the “Zionist-led media”.
