The National Union of Students president has attacked his union's own executive committee over its backing for a series of anti-Israel measures.
Aaron Porter said he did not agree with proposals to send British students on future flotillas to Gaza, or plans to build links with the Hamas-backed Islamic University of Gaza.
Mr Porter, whose term as president ends on June 30, said: "I want to be clear, I don't support that shift in policy, and will be using the time I have left to explain why taking such an extreme position is damaging to both the NUS and Jewish students.
"Under my leadership NUS has worked closely with the Union of Jewish Students to tackle head-on the issue of hate speech on UK campuses.
"For the NUS to hold a policy which is so aggressively anti-Israel does nothing to further co-operation among students on campuses, and I intend to make that point crystal clear to my colleagues.
"I will be doing all I can to persuade the NUS NEC to change its position at its next meeting."
UJS has launched an awareness campaign encouraging students to lobby NEC members and urge them to reverse or withdraw the motion. Postcards featuring images of anti-Israel incidents on campuses -– such as the attack on then-deputy Israel ambassador Talya Lador-Fresher at Manchester University last year - are being sent to campuses alongside briefings for Jewish and pro-Israel students.
It is hoped students will write messages on the cards and send them to NUS head office.
Carly McKenzie, UJS campaigns director, said: "Student officers need to handle this with the same urgency and vigour that they did with hate speech."
Despite Mr Porter's intentions, it is thought an immediate retraction of the policy may be difficult to achieve. The next NUS NEC meeting is not until the end of July, after Liam Burns takes over as president.
The meeting is due to be chaired by Mr Burns and will include new executive members. Mr Burns is believed to hold similar views to Mr Porter, but said he would not comment on union policy until he took office.
Last week's NEC vote shocked Jewish students who had enjoyed good relations with NUS in recent years. Though the Board of Deputies called for the policy to be immediately revoked, the Palestine Solidarity Campaign celebrated "a victory for students".