For ultra-Orthodox Jews, the modern Orthodox – or liberal Orthodox, as they are better known in Israel – tend to be viewed as Reform or Conservative Jews in disguise. There may be basis for these suspicions: Liberal Orthodox Israelis, more often than not in recent years, have been joining forces with non-Orthodox Jews in fighting the ever-tightening hold of the ultra-Orthodox establishment, exercised through the Chief Rabbinate’s office, on key facets of religious life in the country.

But how far are liberal Orthodox Jews willing to push the envelope? A confrontation earlier this week at a closed gathering of world Jewish leaders exposed some of the deep rifts that still exist between progressive-minded Orthodox Jews and progressive-minded Jews of the non-Orthodox ilk, despite having found some common ground.

At issue was whether the liberal Orthodox establishment believes the state should recognize the legitimacy of Conservative and Reform conversions. The response, as delivered by one of liberal Orthodoxy’s most prominent representatives, was a resounding “no.”

Shlomo Riskin, the American-born rabbi who serves as spiritual leader of the West Bank settlement of Efrat, had been invited to address a committee session of the Jewish Agency Board of Governors, convening in Jerusalem this week. The subject of his talk was a new alternative conversion court, spearheaded by a group of liberal Orthodox rabbis in Israel, including himself, to circumvent the Chief Rabbinate. The initiative, known as “Giyur k’Halacha,” is meant to serve Israelis not considered Jewish by religious law, many of them immigrants from the former Soviet Union. It was prompted by the increasingly stringent requirements imposed on individuals undergoing conversions through the Chief Rabbinate.

In a landmark decision, considered a major blow to the Chief Rabbinate’s monopoly on conversions, the High Court of Justice ruled in March that individuals converted in Israel by private Orthodox rabbinical courts should be eligible for benefits under the Law of Return, which grants automatic citizenship and other financial benefits to Jews who immigrate to Israel. Relying on this decision as a precedent, the Reform and Conservative movements subsequently submitted their own petition to the High Court demanding that individuals converted by their rabbis in Israel also be eligible for benefits under the Law of Return.

Non-Orthodox Jewish leaders attending the Jewish Agency gathering on Sunday night had hoped Riskin would express support for their legal case, which is still pending in the High Court, and urge the state to recognize their conversions. Instead, according to participants in the meeting, he said that only conversions performed by Orthodox rabbis are valid in his eyes.

Rabbi Steven Wernick, chief executive officer of the United Synagogue of Conservative Judaism, described the conversation that ensued as “energetic.” Others preferred the term “stormy.”

A prominent member of the Reform movement, who asked not to be identified, reported that Riskin appeared surprised by the backlash. “He usually gets lots of applause from us because we do truly admire him,” he said. “But that wasn’t the case this time around. He met lots of resistance. There was definitely a very vocal response to what he said.”

The non-Orthodox participants at the gathering had not expected Riskin to rule that Reform and Conservative conversions complied with halakha, or religious Jewish law. “But we did expect him, as a well-known advocate of religious pluralism in Israel, to say that our conversions should be recognized by the state,” said the Reform movement member.

When Riskin was challenged, according to sources present at the gathering, he tried to dismiss the relevancy of Conservative and Reform Judaism for Israelis. “He gave us the standard line that the synagogue Israelis don’t attend is the Orthodox one,” reported a participant. “Our response was that maybe it had to do with the fact that Orthodoxy has enjoyed a monopoly on Jewish life in Israel ever since the state was founded, not to mention disproportionately larger budgets, and maybe we should be given a chance as well.”

Wernick expressed disappointment that Riskin was not inclined to use his influence and stature to promote greater acceptance of non-Orthodox Judaism in Israel. “He is doing great things for pluralism in Israel, but only from within Orthodoxy,” he said.

Riskin has long been at loggerheads with the Chief Rabbinate, which does not recognize his conversions and has even tried to oust him from his rabbinical post. The founding rabbi of the Lincoln Square Synagogue on the Upper West Side of Manhattan, he is the founder and chancellor of the Ohr Torah Stone institutions – a network of high schools, colleges and graduate programs in Jewish studies in Israel and the United States. Riskin has been a driving force in promoting greater roles for women in Orthodox communities in recent years, and has also advocated for greater acceptance of the LGBT community in Orthodox congregations.

By breaking with traditional Orthodox views about women and homosexuals, Riskin and his cohorts were seen as natural allies for the Reform and Conservative movements in their struggle for greater religious pluralism in Israel – especially after daring to challenge the Chief Rabbinate not only on conversions, but also on marriage laws. Hence, the disappointment following Sunday night’s gathering.

Speaking with Haaretz Tuesday, Riskin, who described himself as someone who “believes in pluralism very much,” said he found himself in a “difficult position” when asked about the Reform and Conservative conversions. “I don’t think that every conversion has to be accepted,” he said. “There have to be certain fundamental standards – such as immersion in the mikveh, circumcision, and basic knowledge and practice of Judaism – that are universally accepted. I would be foolish to say that I support conversions that others wouldn’t accept.”

Were such standards to be agreed upon, he said, he would not oppose conversions performed by Conservative and Reform rabbis.