Yossi Fackenheim is a 29-year-old Israeli like any other. He proudly served in the IDF and lives and breathes the country. But a judge in the Jerusalem rabbinical court has ruled that he can no longer be considered Jewish.

“Either I’m excommunicated and there’s nothing I can do, or I fight and get justice for a right I thought was mine for life — being Jewish,” said Mr Fackenheim defiantly as he sat in a Swiss Cottage café in north London, discussing a bewildering turn of events.

Mr Fackenheim is the son of renowned theologian and Reform rabbi Emil Fackenheim, who died in 2003. Rabbi Fackenheim’s wife, with whom he had four children, underwent an Orthodox conversion, as did Yossi Fackenheim, when he was aged two and the family were living in Canada.

In 2001, in an Orthodox ceremony, Yossi Fackenheim married his wife Iris in Jerusalem. The marriage broke down. When, in August last year, he went to a bet din in Jerusalem to obtain a get, or religious divorce, he was shocked at the outcome. At the end of a four-hour hearing the rabbinic judge Yissachar Dov Hagar, questioning the level of his religious observance, declared that he had never been Jewish.

“The judge started asking me questions about my observance and decided that I’d given up on being religious before barmitzvah — in fact he did not even ask if I’d had one — and also spoke disparagingly about me being the son of a Reform rabbi and a convert,” said Mr Fackenheim.

He feels that he and the name of his father have “been spat at”, as he spoke out against the decision which he believes sought to punish him for being the son of a prominent Reform rabbi.

“We were given the get on the day, but I received a letter a few weeks later saying I was no longer Jewish, which obviously came as a terrible shock,” he said.

The ruling means he is not allowed to re-marry in Israel, though the Jewish status of his ex-wife has not been affected. He says the ruling “flies against Jewish law, civil law and the whole spirit of what it means to be Jewish”.

Mr Fackenheim’s case has been taken up by the Israel Religious Action Centre (IRAC), the legal branch of the Reform community. Anat Hoffman, IRAC’s executive director, said it would lobby the Higher Rabbinical Court to strike out the line in the get about Mr Fackenheim’s religious status. But she feared that the court would not intervene, “which would leave us seeking a Supreme Court ruling”.

Mr Fackenheim recently received a boost from the Israeli state ombudsman Eliezer Goldberg, who rejected Rabbi Hagar’s ruling, although rabbinic courts are not bound by the ombudsman’s decision.

Mr Fackenheim, who is in Britain studying for a post-graduate degree in drama, is currently living in north London with his sister, who is a member of Alyth Gardens Reform Synagogue. He is passionately intense about the issue. “At the moment rabbis can apparently do what they want to converts — even ones who converted under their very high standards,” he said.

“At a stroke a person’s, and even their children’s, Jewishness can be annulled because they have failed to comply with the letter of the law. I like the fact that you have to work to be Jewish. It’s not a convenience or a fashion. But there must also be an understanding that once you’re a Jew, you’re always a Jew. I’m in no doubt about my identity — I’m just angry at the process.”

Israel Religious Action Centre (IRAC)Alyth Gardens - North Western Reform Synagogue