Zionist Union MK Isaac Herzog will remain opposition leader if Avi Gabbay wins Monday’s runoff for Labor Party leader, Gabbay announced on Thursday morning.Herzog has yet to endorse Gabbay or the other candidate, former defense minister Amir Peretz.“The job of opposition leader isn’t a currency to sell,” Gabbay said. “It is fair and in our interest for Herzog to continue in the job, and I will be happy if he agrees to it.”Gabbay commended Herzog for bringing the party 24 seats in the Knesset and pointed out that there is no requirement to remove the departing Labor chairman from the parliamentary post.“From the beginning, I promised the public that I would be matter-of-fact and fair,” Gabbay said. “I don’t make the old deals that put Labor in the opposition. I do politics differently, and I call everyone to join me. For me, the only promise is to replace Netanyahu.”Peretz told Israel Radio he does not think Herzog will accept Gabbay’s offer and that the opposition leader should be the party’s candidate for prime minister.Giving Herzog the job not only makes it more likely for Gabbay to get the backing of his supporters; it also saves Gabbay the risk of holding a faction vote for an opposition leader, which could be seen as a referendum on whether the MKs have confidence in him. Gabbay cannot become opposition leader because he is not a member of Knesset.With 24 Knesset seats, the Zionist Union – made up of Labor and Hatnua (formerly the Tzipi Livni Party) – is currently the largest faction in the opposition. The law states that an MK from the largest opposition party will be opposition leader, unless most MKs in the opposition vote to choose a different lawmaker.