The head of a legal team fighting to restore a convert’s status as a halachically recognised Jew has warned Jerusalem’s High Rabbinical Court that there would be a “war of the titans” if it did not revoke a judgment that he had never been Jewish.

Anat Hoffman, executive director of the Israel Religious Action Centre, spoke after the court postponed an appeal hearing against a decision by the Jerusalem Beth Din to rescind Yossi Fackenheim’s Orthodox conversion.

The London-based Mr Fackenheim, 29, is the son of the noted Reform theologian Emil Fackenheim, who died in 2003. Because his mother was a convert, the two-year-old Yossi underwent an Orthodox conversion in Canada.

In 2001, he married in Jerusalem in an Orthodox ceremony. But last August, when he and his wife decided to divorce, he was told he was not eligible to give a get, or religious divorce, because his religious status had been questioned. His wife was later issued a get by the beth din.

In May, Mr Fackenheim remarried in Tel Aviv under Reform auspices. Two months ago he and his second wife had twins.

He said: “I’m very frustrated that I’m being delayed in trying to get my Jewish status restored.”