Chief Rabbi Lord Sacks has been urged to take a stand against government plans to introduce marriage for same-sex couples.
Dayan Yisroel Lichtenstein, head of the Federation Beth Din, said: "It is his obligation as chief rabbi to speak out."
While Catholic leaders have been at the forefront of opposition to the proposals, Lord Sacks's office has stated on more than one occasion that he would not be commenting on the issue.
Dayan Lichtenstein said that in America - where
a number of states including New York, have moved to introduce same-sex marriage - "it has become a major issue among the rabbinate. They believe it is their obligation as rabbis to do whatever they can to prevent this happening."
Gay and lesbian couples can currently legalise their union in civil partnerships, and both the Liberal and Reform movements allow Jewish ceremonies for couples who have had a civil union.
Under government proposals – which have been put out for consultation – same-sex couples would be able to go through a civil marriage. But there is no provision yet to allow religious marriage for them.
One senior United Synagogue rabbi, Yisroel Fine of Cockfosters and North Southgate Synagogue, said: "It is up to the chief rabbi what he wants to say or not say."
But he added: "I think it's a sad reflection on society when standards of morality are determined by democratic votes and pollsters, and there are no absolute values.
"We have an important role to play in giving voice to Jewish morality rooted in the Torah. When we can form an alliance with other faiths which have shared values, then we should articulate that voice."
Rabbi Aaron Goldstein, co-chairman of the Liberal Conference of Rabbis, however, argued that the government plans did not go far enough.
"Just as my dad was able to ask God's blessing on our marriage, I hope that I will be able to ask God to bless my daughters' marriages, whether they marry a man or a woman."
But he said that religious groups that did not want to perform same-sex ceremonies should not be compelled to do so.
