Community leaders must do everything possible to encourage grassroots supporters of Israel, according to its deputy ambassador to Britain.

Alon Roth-Snir said last month's We Believe in Israel conference had provided the perfect platform for members of the Jewish community to speak up and challenge delegitimisation and the boycott campaign.

Mr Roth-Snir said: "People want to do something and we have to empower them. This is the challenge. I'm not saying we have to abandon the old way. We still need the leadership doing high-flying things, going to Downing Street, speaking to the government, but we need to empower the grassroots as well. That is what the other side are doing.

"The British Jewish community is very warm and wants to help Israel and wants to participate in this struggle, to walk together. The community should now emphasise grassroots work. The conference was the beginning of a very important project.

"Let's go forward. I am not afraid of criticism. I think we have very good answers. What we have in our backpack is a very good product. I believe Israel is a very good product, but hard to sell."

Mr Roth-Snir is holding the reins at the Israeli Embassy following Ron Prosor's departure last week to New York, where he will represent Israel at the United Nations.

It is thought Mr Prosor's successor in London may be announced within a month, with Jeremy Issacharoff, the Israeli Foreign Ministry's deputy director general for strategic affairs, the current favourite for the role.

Daniel Taub, the ministry's deputy legal counsel, is also among the front-runners. Both men were born in Britain.

Mr Roth-Snir , a career diplomat, previously represented Israel in Jordan and at the European Union, and took over from Talya Lador-Fresher in London last year.

He said the "vibrancy" of the Jewish community in Britain had come as a surprise, but so had the growth of the delegitimisation movement.

"When I served in Brussels I saw it, but there it was the lunatics on both sides. Here in Britain, I feel it is more problematic. It's not the mainstream, but it is not just the lunatics any more."