The heads of the Charedi parties (especially Deri and Liztman) have been going around and proclaiming that they are done with the Likud and Netanyahu and that they will be working to make Yitzchak Herzog, the head of the Labor party the next Prime Minister of Israel.
However, lets take a look at some of the positions of Labor and Herzog:
1. Draft of Charedim - Labor and Herzog are in favor, in fact, Herzog said that he would have voted in favor of the current draft bill that includes criminal sanctions.
2. Women's right - Labor and Herzog were in the forefront against הדרת נשים and are opposed to mehadrin buses.
3. Reform Rabbis - Labor and Herzog support the state recognizing Reform Rabbis and ending the Orthodoc monopoly on Judaism.
4. The "Peace Process" - Labor and Herzog have always pushed for the "peace process" and a Palestinian state and they have no problem with dividing Jerusalem.
On other words, it is clear that Labor not only does not support the Charedim on their big issues, but in fact, Labors positions on these issues are probably worse for the Charedim then the Likud. If so, why are the Charedi MKs pushing Herzog? The answer would seem to be petty revenge. They are very upset with Netanyahu and believe that he betrayed them so they want to take revenge on him. The problem is that they are cutting off their noses to spite their faces.