BDS action at UNSW has turned ugly, with anti-Semitic and Holocaust-denying material appearing on a Facebook page opposing the opening of a Max Brenner chocolate shop on campus. Postings on a Facebook page promoting today's protest have attacked "Jews and Jew lovers" and said the figure of six million Jews murdered by Nazi Germany was an exaggeration.

"Tell us again how there was no hidden Zionist agenda with the Holocaust and the eventual creation of the state of Israel," one reads.

The Prime Minister said yesterday through a spokeswoman that the government had always been firm in its opposition of the BDS movement, which equates Israel with apartheid-era South Africa.

"This campaign does not serve the cause of peace and diplomacy for agreement on a two-state solution between Israel and Palestine," she said.

"I welcome the strong ties our universities have with Israeli researchers and academic institutions, and I hope those ties will deepen in the years ahead."

The University of Sydney Student Representative Council this month called for a boycott of Israeli academic institutions, including severing the university's ties with the world-renowned Technion in Haifa.

The Prime Minister's comments come a week after she became the first Australian politician to sign the London Declaration on Combating Anti-Semitism.

"In the face of anti-Semitism, there can be no bystanders," she wrote. "As citizens, as leaders and as nations, we must act."

The gesture has been seen as bridge-building after a row with the Jewish community last year over Australia's abstention from a UN vote giving Palestine non-member observer state status.

Executive Council of Australian Jewry chief Peter Wertheim welcomed Ms Gillard's remarks yesterday.

"The BDS campaign against Israel over the last few years has been a spectacular failure," he said.

"It has been forcefully repudiated by every political party represented in the federal parliament and in every state and territory parliament."

Some Greens, including NSW senator Lee Rhiannon, have backed the movement in the past. Support for BDS is credited with dashing the Greens' hopes of winning the seat of Marrickville in the 2011 NSW election.

The group Students for Justice in Palestine has called for a boycott of the University of NSW Max Brenner outlet, due to open in June.

BDS activists claim the chain is owned by the Israeli Strauss Group of food and confectionery manufacturers, which produces some rations for the nation's defence forces and accuse it of complicity in "Israeli war crimes". However, the local management insists it is wholly Australian owned and operated.

Australian Union of Jewish Students spokesman Andrew Goldberg said: "The boycott Max Brenner movement has turned into a hotbed of blatant anti-Semitism. Classical anti-Semitic comments have been made, clearly irrelevant to discussion about Max Brenner. The organisers have effectively endorsed these comments by dismissing legitimate concerns about anti-Semitism as 'trying to shut down debate about Israel'."

Mr Goldberg called on university officials to "ensure that those with an anti-Semitic agenda will not be allowed to spread their hateful and discriminatory agenda on campus".

The Australian was unable to contact the Facebook site's operators. However, one prolific poster apologised "to any of the Jewish people on this page who were upset and offended by comments".