A rabbi is causing an uproar in Israel’s strictly Orthodox community with a new book in which he insists that there is no Halachic basis for the annulment of conversions.

Rabbi Haim Amsalem, a Shas MK, has been told by his party’s leaders in the past to rein in his zeal to publish Halachic rulings.

One of the party’s ministers even said recently: “He has to decide whether he’s a politician or a rabbi.”

But Rabbi Amsalem is undeterred and his latest book, soon to be published, contains a bombshell.

He writes that the practice of canceling Giyur retroactively has no basis in Jewish law and that, once a Rabbinical court has converted someone, he or she is a Jew for all purposes. No matter how they practice their religion, they remain a Jew.

In recent years, a growing number of Rabbinical courts in Israel and other countries have cancelled Giyurim after receiving evidence that the convert has not acted as an Orthodox Jew.

In the past, annulment of giyur was extremely rare and many rabbis opposed it. In some cases, even women seen wearing trousers were threatened with annulment of their conversion.

Rabbi Amsalem also believes that the requirement for life according to strict standards of Halacha as a condition of conversion is excessive and it is sufficient for a convert to live “a traditional Jewish lifestyle, like most Israelis today, even if he doesn’t keep all the mitzvoth”.

He is also in favour of giving special status in the conversion process to candidates who are “of Jewish origin”, even if their mothers are not Jewish, and he accords special status to candidates who serve in the IDF.

An intense campaign has been waged against Rabbi Amsalem in recent months to prevent him from publishing his book. The Charedi daily newspaper attacked him, quoting rabbis and dayans who “expressed contempt for the boastful and heretical statements of the Shas MK who called for the conversion of Russian goyim”

Despite the pressure, he said this week that he is going ahead with publication. “They are carrying out a witch hunt against me,” he said in an interview.

He hinted that a recent report of a nepotistic appointment of his son was orchestrated by rival rabbis, but vowed to continue publishing his views.