In a bid to stem defection of voters from Shas to Israel Beiteinu, Rabbi Ovadia Yosef warned on Thursday that anyone who votes for Avigdor Lieberman's party is a transgressor whose sin will never be expiated. "If someone plans on voting for a party that is in favor of assimilation, of selling pork, then his sin is too great to bear, his sin will never be forgiven," the Shas mentor said in a televised appearance without explicitly mentioning Israel Beiteinu's name. A source in Shas estimated that the party had lost as much two mandates to Lieberman, which, he said, explained Shas's fall from 12 Knesset seats in the 2006 elections to about 10 seats in current election surveys. "There is the hard core of haredi Sephardim, who will continue to vote for Shas, and there is a larger group of tradition Sephardim who light Shabbat candles but go to soccer games on Saturday morning. This second group is attracted to Lieberman's hard line on Israeli Arabs and the impression of being decisive," the source said. Shas's main criticism is directed at Lieberman's support for a type of civil marriage called "the union of couples" (brit hazugiut). Since the establishment of the state all marriages and divorces of Jewish Israelis have been controlled by the Orthodox Rabbinic establishment. As a result, Jews are not permitted to marry non-Jews, which prevents assimilation, although mixed marriages performed abroad are recognized by the state. There are about a quarter of a million Israeli citizens who immigrated under the Law of Return but who are not Jewish according to Orthodox Jewish law, and who cannot marry in Israel. Israel Beiteinu intends to push for a change in the religious status quo that would enable these non-Jews to form a type of marital union recognized by the state. MK David Rotem, No. 8 on Israel Beiteinu's candidates list and an Orthodox Jew, rejected Shas's attack on the civil marriage initiative. Rotem argued that the amendment would reduce the likelihood of mamzerut - the birth of children as a result of an illicit sexual relationship. "In consultation with religious Zionist rabbis, we created a type of union that does not constitute a full-fledged marriage according to Halacha. This prevents a situation in which a woman who is married according to Halacha will have an illicit sexual relationship with a man who is not her husband," he said. Meanwhile, Haredi political parties are concerned that the rise of Israel Beiteinu will hurt their bargaining power in the next government coalition. Two leading haredi weeklies - Hamishpaha and Bakehila - featured analyses on how the rise of Israel Beiteinu could hurt Shas and United Torah Judaism. Ya'acov Rivlin, senior political pundit for Bakehila, speculated that a strong Israel Beiteinu might bring about a haredi-free government coalition based on Likud, Kadima and Israel Beiteinu. "Bibi [Likud chairman Binyamin Netanyahu] would have to be crazy to do it... but in a political system the very possibility that this might happen is weakening Shas and United Torah Judaism. "These two parties might end up in the coalition, but at a much lower premium than previously thought," Rivlin said. Yossi Elituv warned in Hamishpaha that the rise of Israel Beiteinu signaled the undermining of the religious status quo. "Hundreds of thousands of immigrant goyim who are fed up with the religious establishment are roaring for Lieberman," Elituv wrote. "His followers include a large swathe that will demand reforms in the minimalist religious character that remains in Israel. Huge populations are calling to dismantle the status quo."