The Chief Rabbi of Israel, Shlomo Amar, is to convene the entire Grand Rabbinical Court to overturn a previous ruling that could revoke thousands of conversions made over the past decade.

Three of the more conservative dayanim [religious judges] from the Court last week published a ruling that said that all the conversions performed by the special giyur [conversion] courts were “null and void”.

The implication of the ruling is that over 15,000 converts who passed through the special court system, headed by Rabbi Haim Drukman, may not be allowed to get married under the Israeli legal system, which recognises Israeli marriages only if they are performed by religious authorities.

The court upheld a previous local rabbinical ruling in a divorce hearing which decided that a women did not need a get since her conversion was invalid and she was effectively not Jewish. In both cases, the dayanim were reflecting the position of many strictly Orthodox rabbis, who oppose what they see as wholesale conversions taking place in the special courts and accuse Rabbi Drukman of allowing non-Jews into the Jewish people.

Rabbi Amar has been trying to steer a course between both sides, but in recent months has backed Rabbi Drukman’s efforts. Over 300,000 new immigrants have entered Israel under the Law of Return, despite being non-Jewish, according to halacha. Former Prime Minister Ariel Sharon said in the past that helping them to convert was “a national mission”.

The ruling caused an uproar among organisations working with new immigrants and liberal Jewish movements. Rabbi Amar promised the Absorption Minister, Yaakov Edri, that he would convene the full plenum of the Grand Rabinnical Court to overturn the ruling.