It is highly unusual, to say the least, for a rabbi in today's Israel to be a hero, not just among the religious crowd, but also among a secular population increasingly alienated from, if not indeed antagonistic towards, the rabbinical establishment and all it represents. Rabbi Haim Amsellem is such a man. For many Israelis, he is a whistle- (or maybe shofar-) blower, warning of the extremism that is fast becoming the norm of Israel's religious life.

First elected to the Knesset as a member of Shas, the Sephardi Orthodox party, in 2006, Rabbi Amsellem had been a community rabbi in both Israel and Switzerland. Having studied under some of the leading Sephardi rabbis in Israel, he gained the reputation as a talmid chacham, subsequently strengthened by the halachic responsa that he published as his career developed.

Early in 2010, he published Zerah Yisrael (Seed of Israel), where he argued strongly for a more flexible attitude toward conversion. Faced with 300,000 immigrants from the FSU not considered halachically Jewish, the rabbinic establishment has been pussyfooting for years, torn between their loyalty to the tradition as they define it, and the obvious need to prevent a future demographic disaster.

Haim Amsellem offered a third way in his discussion of the halachic literature - to treat soldiers with Jewish fathers or some other tangible Jewish ancestry, differently and more leniently than a prima facie non-Jew. "The approach has to be simpler," he said in an interview in his Knesset office. "I brought halachic sources showing that someone willing to keep Shabbat, eat kosher food, do the basic mitzvot - and to put themselves on the front line [ie joining Israel's army] - showing their willingness to "suffer for Israel" [according to the Talmudic phrase] - demonstrates tangible proofs of their seriousness."

In addition, he took the view that Charedim should serve in the army as well as to study basic subjects such as maths and English in order to prepare themselves for the workforce. He would exempt only an elite of Torah scholars.

If serving in the IDF Has a Jewish value, the charedi world has a problem

Amsellem's book brought howls of protest from both Sephardim and Ashkenazim. By linking conversion to army service, he was by definition challenging most of today's Charedim: "If serving in Tzahal [the IDF] has a Jewish value, then the Charedi world has a problem," he said. "Why don't Charedim say the blessing for Tzahal in their synagogues - because it is part of Zionism and the army is not one of the tzaddikim? [saints]. And if they said it, they would have to ask why don't we serve and deserve a blessing? Whatever is connected to the army, they negate."

What angers Amsellem no less is that fact that the Sephardi world seems to be following the lead of the anti-Zionist Ashkenazim. He recalls how the Shas party was proposed by the late Rabbi Shach, a Lithuanian, because he wanted to separate Sephardi from Ashkenazi Charedim. "Now the Shas party leaders - who were elected to represent the traditional Sephardi voter - have subjugated themselves entirely to the Lithuanian-Ashkenazi Charedim, who as a result have increased their voting power in the Knesset to 20 mandates, five of their own United Torah party and 15 of Shas. When I was elected to the Knesset, I brought with me French-speaking, Zionist voters. I am beholden to these people, not to the Shas party."

The Shas party, under Eli Yishai and his mentor, Rabbi Ovadia Yosef, attempted to oust Amsellem from Shas, but this was impossible. Today, Amsellem sits in the Knesset but is isolated from Shas.

Amsellem declares his intention to establish his own party: "I have growing support for such a step," he says, citing independent surveys. "They include 33 per cent of Shas voters." Beyond Shas, he also has the growing backing of senior army people, engineers, doctors, lawyers, academics - people who wish to fuse Torah observance with the work ethic. "This approach has recently been marginalised; the secularists took it to one extreme, the Charedim to another. Our way, of Torah V'Avodah, is disappearing. We want to return to this model."

To demonstrate the strength of his support he holds up a large attaché case bulging with papers: "These are letters and e-mails I've received just in the last month."

Algerian-born Amsellem - aged 52 and father of eight - openly criticises Shas for deserting "the way of the Sephardim, which is tolerant, welcoming, forgiving and loving all Israel." He is for a religious voice in politics: "We need money and power. I'm not against this. What we need is to separate rabbis from politics," he said.

"For rabbis who have institutions paid for one way or the other by the state to be involved in politics is unacceptable. If a rabbi wishes to run for the Knesset, let him leave his institution and present himself as a candidate for election.

"We are Sephardim. We want to be integrated, to work, to serve in the army. What is there to understand? But Shas doesn't understand this."

Did he consider himself a rebel, a revolutionary? He smiles at the analogy before saying: "You could say I'm a freedom fighter."