Communal organisations and grassroots groups must work together to tackle the threat posed by the boycotts, divestment and sanctions movement, delegates were told at the We Believe in Israel conference.

Jonathan Turner, the chairman of UK Lawyers for Israel, said "fabulous factual information and early warnings" provided by "outstanding activists" in grassroots movements were key in the fight against the boycott campaign.

He said: "It is one of the most useful things that we have."

Speaking at a session that looked at the impact of grassroots pro-Israel campaigning, regional groups from Yorkshire to the West Midlands and Brighton said they were reliant on support from the secular and Christian communities.

Scottish Nigel Goodrich, who is not Jewish, has formed Edinburgh Friends of Israel and Glasgow Friends of Israel to combat the strong boycott movement in those cities. He said: "The BDS movement in Scotland is viral. It is nasty and in your face. I have come here to bring people together - Jewish, secular and Christian."

Antony Dennison, co-chair of North West Friends of Israel, said the threat to shops like the Israeli-owned Kedem store in Manchester, did not come from Muslim pro-Palestinians. He said: "The Muslim community continue the interfaith discussions - we educate them, they educate us. The real enemy are the left-wing anarchists who are antisemitic."

Fiona Sharpe, of Sussex Friends of Israel, said that "winning the communications battle is at the core of what the grassroots movements are doing. What we're doing is taking the message that it is OK to be Jewish, it is OK to be Zionist. It is OK to stand up and say that in public."

She urged the community to stand up to the "bullies" behind attacks on Israel. "For too long we have been quiet. We are not going to stand for antisemitism or anti-Zionism. There is a crossover. You scratch hard enough at any anti-Zionist feelings, and there is antisemitism there."

Simon Johnson, chief executive of the Jewish Leadership Council, outlined five ways of tackling BDS - lobbying, political pressure, media pressure, grassroots activism and legal pressure.