In addition to the chairman of the Histadrut, members will also vote for leadership of the various institutions within the organization, including its committees and regional councils.
Histadrut elections are held every five years and all unionized workers who joined the organization at least six months prior may vote. Currently, 535,307 workers are eligible to vote in this year's elections.
The Yachimovich headquarters issued a statement saying, "The battlefield is abuzz. There is a good chance that within the next 48 hours, Yachimovich will be the new chairman of the Histadrut."
Yachimovich has been aggressively campaigning for the position, holding rallies throughout the country. Yachimovich's campaign also took pride in the fact it was able to recruit some 10,000 volunteers to campaign for her.
In response to Yachimovich, Nissenkoren issued a statement saying, "We have transformed the Histadrut into a social movement. We are confident that workers and pensioners will express their faith in us and we will win a clear victory and continue with social actions, not just words."
The two candidates have conducted one of the stormiest election campaigns in recent memory.
Yachimovich, who wants to be the first woman to head the organization, has accused Nissenkoren of having ties to the corrupt officials, including the former chairman of the Histadrut, Ofer Eini.
In response, Nissenkoren accused Yachimovich of corruption following the release of a recording detailing a secret quid pro quo deal between Yachimovich and MK Eitan Cabel for mutual promotion. Cabel was running for leadership of the Labor party.