The annulment of Yossi Fackenheim’s conversion has yet again called into question the conduct of Israel’s rabbinic courts. Not only is the fact that he is the son of one of the 20th century’s leading Jewish theologians bound to produce outrage over his treatment; so, too, is the very idea of retroactively stripping a person of their Jewish status.

Rabbi Jonathan Romain, chair of the Assembly of Reform Rabbis UK, sums up the strength of feeling about the Fackenheim affair. The court’s decision runs “counter to the principles of Jewish status, under which conversions cannot be annulled — otherwise they would always be tentative and the status of any descendants always open to challenge,” he said.

Yossi Fackenheim’s late father, Emil, he added, “inspired millions of Jews when he said that after the Holocaust there was now an additional 614th commandment: ‘Thou shalt survive; thou shalt not give Hitler posthumous victory’.

“It is sad that Fackenheim’s heritage was able to survive Hitler, but not the Israeli Chief Rabbinate.”

Although a conversion can be revoked if the rabbis subsequently find evidence that the convert was insincere at the time of adopting his new faith, the practice is controversial.

Last year Israel’s Supreme Rabbinic Court caused uproar when it not only invalidated the conversion of a Russian immigrant but also ruled that all conversions performed under the aegis of the head of Israel’s National Conversion Authority, Rabbi Haim Druckman, should be null and void.

That extraordinary edict was attacked by many Orthodox rabbis across the world and even though Israel’s Chief Rabbinate has not endorsed the court’s decision, thousands of converts in Israel have been left with doubt cast over their Jewish credentials.

One Orthodox rabbi in America wrote of the episode on the Orthodox website Cross-Currents: “As a rabbi of a synagogue, I can say that there are many, many people, sincere geirim [converts], who are frantic with worry about their personal status, and deeply concerned that at some point in the future a bet din with an agenda will in a presumptive manner declare them all to be gentiles. It’s a scandal.”

The practical implications could be far-reaching. Converts suddenly finding themselves declared non-Jewish years after their conversion could be prevented from marrying other Jews in Israel, since the country has no civil marriage.

While both these cases could be seen as simply the idiosyncratic verdicts of individual courts, to some they reflect a much wider battle over conversions in Israel. There are two, separate issues. The first concerns an estimated quarter of a million immigrants who came in the great influx from the former Soviet Union in the 1990s but who are not considered Jewish by Orthodox definition.

Some believe rabbinical courts should take a lenient rather than stringent stance towards accepting such people if they choose to convert. Rabbi Benjamin Lau, nephew of a former Israel Chief Rabbi, put the case for a more pragmatic conversion policy when he spoke to a London audience last year. “If we find ourselves in a situation that the rabbinate in Israel tried to push people out instead of connect[ing] people,” he said, “something is wrong in the system.”

Then there is the situation of potential immigrants from the diaspora. Both Orthodox and Progressive converts from abroad have been eligible to come to live in Israel as Jews under the Law of Return. But in recent years Israel’s Ministry of Interior has moved to exert greater control over admissions, setting conditions which have blocked the entry of some foreign converts.