Defeated Labor leadership candidates Isaac Herzog and Erel Margalit announced Friday that they would support MK Amir Peretz in Monday's runoff race against former environmental protection minister Avi Gabbay.Herzog and Margalit finished third and fourth in Tuesday's first round of voting. They were both wooed by Gabbay, who visited both at their homes, but decided to endorse Peretz instead."Sitting on the fence is not an option when matters of essence must be decided," Herzog said after many of his advisers and supporters urged him to remain neutral. "Amir's combination of experience on security, diplomaticand socioeconomic issues tipped the balance for me. Experience is important for leadership, and Amir's advantage was clear."Herzog said he did not receive anything in return other than commitments to maintain the Zionist Union, the partnership with MK Tzipi Livni, and efforts to build a larger political bloc ahead of the next election.MKs Ayelet Nahmias-Verbin and Manuel Trajtenberg, who supported Herzog in the first round of voting, also backed Peretz.At a hastily called Tel Aviv press conference, Margalit said he decided to endorse Peretz because he connected to him on socioeconomic, security and national issues. "What Netanyahu has destroyed, we will build back together," Margalit said. Both Margalit and Peretz emphasized at the press conference how little they have in common but said they could complement each other well. Peretz said they would restore hope for people who have given up on the possibility of achieving peace."My experience and his innovation together can serve the people and State of Israel and help bring down the government of Netanyahu," Peretz said.During the campaign, Margalit called Peretz corrupt and called upon him to quit politics, due to irregularities in his party membership drive, and Peretz repeatedly mocked Herzog's idea of building a Center-Left bloc.Gabbay received an endorsement Friday from MKs Eitan Cabel, Miki Rosenthal and MK Zoheir Bahalul, who heads the party's Arab sector. Rosenthal supported MK Omer Bar-Lev in the first round of voting."In his short time in politics, Gabbay has proven his uniqueness," Bahalul said. "He is not scared of making difficult decisions, he has a backbone of values, and he is a doer. I believe in his ability to work together with me to connect Labor to the Arab sector and build young Arab leadership in the party."Former MKs Ophir Paz-Pines, Michael Bar-Zohar, and Amir Ayalon also endorsed Gabbay on Friday. Zionist Union MK Stav Shaffir remains on the fence, though she is thought to support Gabbay as well."Avi is a good man who gives us real hope of stopping the 40 years of right-wing rule," Cabel said. "I think that with Avi, for the first time in years, we can persuade new sectors to believe in us and support our path."