A conference on justice for Palestine due to be held tomorrow at State Parliament has been called off after several high-profile speakers withdrew from the event, citing revelations the convener had made anti-Semitic remarks.

Maqsood Alshams, who had organised the conference 'Injustice anywhere is a threat to justice everywhere', made a series of derogatory remarks about Jewish people in several private emails, the Herald revealed on Wednesday.

Two of the conferences key speakers, Antony Loewenstein and Peter Manning, withdrew in a joint email to the convenor at lunchtime today [Wednesday].

"As a Jew who condemns anti-Semitism I though it would be inappropriate to engage in a debate in that kind of environment," said Mr Loewenstein, a blogger and author of My Israel Question. "That does not change the fact that I still feel very strongly about the situation in Gaza."

Professor Manning, who lectures in Journalism at UTS and is a critic of anti-Arab media bias, also said he felt the conference was no longer an appropriate forum for the issue.

"I don't want to confuse the Palestinian issues that I care about with any form of racism or anti-Semitism," said Professor Manning.

Mr Maqsood, a Bangladesh-born asylum seeker and founder of the small lobby group Asia Pacific Human Rights Institute, apologised for the emails on Tuesday and said he had been "intoxicated and angry" when he wrote them.

He was not available for comment tonight [Wednesday], but had notified people via email during the afternoon that the event had been cancelled.

The director of the NSW Jewish Board of Deputies Vic Alhadeff, who condemned Mr Maqsood's comments on Tuesday, said he was vindicated by the decision.

"Our community felt from the outset that if the conference went ahead, it would have been irredeemably tainted with bias, given the lack of balance and the anti-Semitic comments made by the principal organiser," he said in a statement.