Thirteen days ahead of the election and two days before the deadline, most of the veteran parties had signed surplus vote-sharing agreements by Wednesday.
Under the Knesset Elections Law of 1969, after an election:
The first thing that must be determined is the "threshold," the minimum number of votes that a party must receive to gain representation in the Knesset.
The electoral threshold is 2 percent (it was 1% before 1992 and 1.5% from 1992-2003). Therefore, a party must win at least 2% of all the properly cast votes to gain representation. (Votes that are not cast properly are discarded and play no part in the calculation of the mandates).
Once the threshold number is determined, the votes received by parties that failed to reach it are ignored in any further calculations. They are, therefore, "wasted" votes.
The total number of properly cast votes received by the parties that exceeded the threshold is then divided by 120 (the number of Knesset seats) to determine the numeric equivalent of one mandate. The "surplus votes" remaining to each party after its mandates have been accounted for are not considered in this first round of the calculations.
Because of the surplus votes that each party receives and that are not taken into account in the first round of calculations, the number of mandates allocated in this round will fall short of 120.
That's where the vote-sharing agreements come in.
There is then a second round of calculations, in which an "internal index" is established for each party, or for each pair of parties that has reached a reciprocal vote-sharing agreement.
The internal index is determined by dividing the total number of votes the party has received, or the pair of parties has jointly received, by the number of mandates allocated to it in the first round, plus one.
For example, if a mandate is fixed at 25,000 and a party or pair of parties receives 115,000 votes, the internal index will be the result of 115,000 divided by five.
The remaining Knesset seats are distributed to those parties with the highest internal index. The calculation is made one mandate at a time until all the mandates that were not distributed in the first round have been allocated.
If a pair of parties end up with enough votes to receive an additional mandate, the Knesset seat will be allocated to the party with the higher internal index.
The Central Election Committee said on Wednesday that the parties can submit their signed surplus-vote agreements until Friday. The pairings will be published early next week.
Likud and Israel Beiteinu signed a vote-sharing agreement six weeks ago in an attempt to keep their votes in the right-wing bloc. Similarly, an agreement was signed between Labor and Hatnua Hahadasha-Meretz, in an effort to strengthen the Left.
Habayit Hayehudi signed a vote-sharing agreement with the National Union, even though Habayit Hayehudi chairman Daniel Hershkowitz was reluctant to do so.
"We deliberated whether we should sign with the National Union, which decided to divide the national camp by seceding from Habayit Hayehudi, and to prefer other considerations instead of the benefit of the entire camp," he said.
By Wednesday, Shas had not signed yet an agreement but it will most likely sign one with United Torah Judaism, as it has in the past.
Surprisingly, Kadima, which did not sign a vote-sharing agreement for the 2006 elections, this time signed on with the Green Party headed by Pe'er Visner.
"Kadima is a party that has green issues close to its heart and we have decided that out of all parties that promote green issues, the Green Party was our first preference," Kadima faction chairman Yoel Hasson said.
The Gil Pensioners Party chose to cooperate with Tzabar - the Israel Youth Party.
"We thought that cooperating with a party that speaks to the young voters goes perfectly well with a party that turns to elderly voters," a Gil spokesman said.
The United Arab List-Ta'al has signed a deal with fellow Arab party Hadash. Several new parties, such as Ephraim Sneh's Yisrael Hazaka, have not reached any agreements yet.
Dan Izenberg contributed to this report.
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