The chairman of the Tzohar national-religious rabbinical organization, Rabbi David Stav, excoriated Sephardic Chief Rabbi Yitzhak Yosef Tuesday, and threatened to sue the Chief Rabbi for libel over recent claims against Rabbi Stav.

Speaking with Arutz Sheva, Rabbi Stav accused Rabbi Yosef of undermining the state conversion system, citing recently revealed comments made by Rabbi Yosef last week at a rabbinical conference in Jerusalem.

“I think we are facing something today something which we have never been exposed to. The head of the system… questions the validity of the conversion that he signed,” said Rabbi Stav.

“As a matter of fact, he points out that one of the rabbinic judges’ ‘big sin’ is the fact that he was a lawyer in the office of Supreme Court judge Elyakim Rubenstein. He is a big scholar, he is a big talmid hacham [rabbinic authority], he is yireh shamayim [God-fearing], but all of his conversions – we’re talking about thousands of conversions – need to be rechecked.”

Rabbi Stav added that he planned to sue Rabbi Yosef, after the Chief Rabbi claimed that Rabbi Stav and Rabbi Shlomo Riskin, chief rabbi of the town of Efrat, had performed hundreds of ‘quickie’ conversions in Brazil.

Rabbi Yosef “accused me for converting 400 converts in Brazil – something that has never occurred. I’ve never been there, I’ve never converted anybody there,” Rabbi Stav continued.

“Maybe the biggest message that was given today, is [the claim] that the reason why the State of Israel has brought to Israel so many immigrants, Jewish and non-Jewish maybe, is just because the state wanted to reduce the influence of haredi parties, which is something that is hard to hear.”

“To think that our evaluation of Jews or immigrants that arrive to the State of Israel is dependent on the party they vote for is sad, it is very sad.”

“Personally I am planning to sue Rabbi Yosef for saying a lie – something that he knows is a lie against me and Rabbi Riskin, maintaining that we… converted these 400 people in Brazil, something that has never occurred. Yes, I intend to sue if he does not apologize.”

“I would like to separate between two categories of immigrants. Those that the father is Jewish – although halachically [according to Jewish law] he is not Jewish, but the fact that his father is Jewish and he suffered from anti-Semitism and he feels Jewish and he wants to be a part of the Jewish people – that is one group.”

“The second group,” non-Jewish immigrants who immigrated as the grandchild of a Jew or the spouse of a relative of a Jew “which many times doesn’t feel connected to the Jewish people, this issue should be discussed. We should reevaluate the Law of Return.”

Yediot Aharonot revealed Tuesday morning footage taken from a conference last week, in which Rabbi Yosef can be heard lamenting the immigration of hundreds of thousands of non-Jews to Israel under the Law of Return, claiming the immigrants have empowered anti-religious elements in Israel.

Rabbi Yosef also accused rabbis Stav and Riskin of performing 400 ‘quickie’ conversions in Brazil, while also castigating a rabbi in the Chief Rabbinate’s conversion authority, disqualifying the conversions he performed.