While no agreements have been finalized yet, former justice minister Tzipi Livni is being wooed by both Labor leader Isaac Herzog and Yesh Atid leader Yair Lapid as part of the center-left parties' attempt to form a united front against Prime Minister Benjamin Netanyahu.
Both Herzog and Lapid have offered to reserve the second spot on their respective parties' list to Livni.
Labor has also offered Livni to reserve another spot for one of the members of her own Hatnua party in the top ten of the would-be joined faction.
Livni and Herzog, who both traveled to Washington over the weekend to attend the Brookings Institute's annual Saban Forum, were seen discussing their potential joint run in the halls of the lavish Willard InterContinental hotel in the American capital.
"I told my wife I was going to invest in some couplehood with Tzipi over the weekend," Herzog said with a smile at the Saban Forum.
The Forum convened in Washington to discuss the US-Israel relations and ways to achieve peace, with speakers like former secretary of state Hillary Clinton and US Vice President Joe Biden, but those in attendance were more interested in internal politics in Israel.
During a talk with Herzog at the Saban Forum, interviewer Jeffrey Goldberg addressed views in the Israeli media and in parts of the public that the opposition leader was a "non-charismatic figure," asking him how he was going to handle the "barriers to (his) success among the Israeli voters."
"Do you know how many charismatic leaders we had, and where they led us to?" Herzog replied, declaring that he "intends to win these elections and form a government."
Prof. Manuel Trajtenberg, an Israeli economist who was appointed in 2011 to head a commission to examine and propose solutions to Israel's socioeconomic problems, is also in Washington, and Livni and Herzog were holding talks with him to offer him the job of finance minister.
The joint Labor-Hatnua alliance would operate in the same model as the one between Likud and Yisrael Beitenu in the 2013 elections, according to which both parties ran as part of one list, but maintained their separate organizations.
It also appears that Kadima leader MK Shaul Mofaz will join the Labor party and receive a spot in the top ten, with the joint list including Kadima as well.
Meanwhile, Yesh Atid leader Yair Lapid is in a better position to offer Livni a spot on his list, since the decision is his alone and is not conditioned by the approval of the party, like in Labor's case.
As of Saturday night, it appears Livni was close to reaching an agreement with Herzog.
Senior Labor officials criticized the reserved spots Herzog was offering Livni, claiming he was "selling out the party," wondering "what is the point of primaries with all of these reserved spots? MKs worked hard, and then they're just kicked off the list."
To soften internal criticism within Labor over the promise to reserve spots for Livni and another Hatnua member, Herzog and party chairman MK Eitan Cabel presented a poll showing that such a union will lead to over 20 Knesset seats.
"We need this union for the success of the (center-left) bloc in the elections," Cabel said. "If there's a chance for us to be bigger than the sum of our individual parts, then it's worth it. According to the polls, if Livni runs with us, both sides stand to gain. I understand the candidates' concerns; we'll do whatever we can so everybody wins in the end."
Diplomats and politicians who attended the Saban Forum said the "main patron" for this would-be union between Livni and Herzog was former president Shimon Peres, formerly a key figure in Labor himself.
A diplomatic source said Peres offered to nominate him for foreign minister if he joins the united list and helps strengthen Herzog.
Sources close to Peres said Saturday that while he supports a union of a centrist bloc that could offer a better future for Israel, he was not involved in the talks.