The center left and center right blocks seem not to have moved at all relative to each other. It almost seems like there are two different elections going on, one for who will compose a minority center-left block and who a majorty rightist block. If there's any discussion going on of what would move a Likud Beitenu voter to the center-left, it doesn't seem to be surfacing in Haaretz articles.
International investigators to probe several cases of Syria chemical attacks (AP)
from the article: Poll: Likud-Beiteinu losing more ground to Habayit Hayehudi