Rabbi Shmuel Auerbach, who heads the haredi stream known as the “Jerusalem faction,” has decided to back the Yachad-Ha’am Itanu party under Eli Yishai, according to Channels 2 and 10.

The instruction to vote Yachad will apparently not be openly announced, but will either be published in the stream’s newspaper, Hapeles, or simply be communicated by word of mouth.

If the reports pan out, the decision is expected to have a momentous impact on the election results, since the Jerusalem Faction’s support will almost undoubtedly carry Yachad pass the threshold required to enter the Knesset. The party has been polling at 4 or 5 MKs, but some polls have put it dangerously close to the threshold, or beneath it.

A failure by Yachad to pass the threshold would mean a loss of over 100,000 votes from the religious-nationalist camp.

The decision to support Yishai was reportedly made after Yachad’s patron rabbi, Rabbi Meir Mazuz, promised Rabbi Auerbach in writing to do all he could oppose the Enlistment Law.

The Lithuanian-haredi Jerusalem Faction split off from United Torah Judaism and its voting potential is estimated at tens of thousands of votes. It is adamantly opposed to the Enlistment Law that requires haredi men to enter military service. The possibility that the stream would support Yachad, which is Sephardic, with a strong religious-Zionist and pro-IDF element, was initially highly unlikely, but Shas reportedly would not give Rabbi Auerbach the same kind of commitment to oppose the Enlistment Law that Yachad did.

With the elections being as close as they are, Yachad’s success or failure to pass the threshold could make the difference between a Likud-led government and a unity government, one led by Labor, or some kind of deadlock. Meretz and Yisrael Beytenu are also not far from the threshold. A failure by Meretz to enter the Knesset would be a severe blow to the Left.