Campaigners are being given lessons in combating anti-Israel rhetoric in the media.

Around 30 people took part in the Zionist Federation's Writing Course for Israel Advocates in London on Sunday where they learnt about writing letters to the editor, effective blogging and how to respond on forums, Facebook and Twitter.

The course was led by journalist David Harris, director of research and content at The Israel Project, a non-profit organisation which provides information about Israel to the press.

Among the participants was Joseph Heller, a strictly Orthodox speech- writer from Hendon whose yeshiva roommate became a member of anti-Zionist group Neturei Karta. Mr Heller, a 50-year-old father of six, said: "I feel it's my responsibility to stand up for Israel in the Orthodox community.

"I was in yeshiva for seven years and dormed with a man who came from a normal background but met people, was influenced by them and excited by their ideology. Now he is frequently photographed on the Palestine side of demonstrations and is in Neturei Karta. This course has opened my eyes to techniques and tactics."

Oliver Manyemba, a 50-year-old Christian lecturer originally from Zimbabwe, said he had signed up to the course to help combat anti-Israel activities on campus.

Mr Manyemba, who teaches at Cass Business School in London, said: "There is a very strong Muslim group of students who are very outspoken against Israel. There are Jewish students who don't have the confidence and are too scared to speak out in support of Israel.

"I want to develop writing skills to influence young people, Jewish and non-Jewish, to make sure they are informed before they make decisions."

Another Christian, Greek-born teacher George Koutroukis, 32, from Golders Green, was keen to confront anti-Israel rhetoric online.

He said: "I often write on chat rooms and blogs. I feel that Britain is one of the most anti-Israel countries in the West. I have learnt that when responding to anti-Israel content, you should put your main point in the first paragraph, and give your real details, as this gives legitimacy."