In a dramatic reshuffle on the Israeli left, former prime minister Ehud Barak has decided to run on a joint list with the Meretz party in the September election under the name Democratic Camp.
Mr Barak (77) retired from politics in 2013 but returned a few months ago to form his own party, saying he was determined to end prime minister Binyamin Netanyahu’s “rule with the radicals, racists and the corrupt”.
Mr Barak agreed to take the number 10 slot on the joint list but will have the first pick of a ministerial portfolio in the unlikely event that Democratic Camp forms part of the next government.
Israelis will go to the polls again on September 17th, after Mr Netanyahu failed to form a coalition of right-wing and religious parties following a vote in April, due to disagreements over military service for the ultra-Orthodox.
Heading the new list will be Meretz leader Nitzan Horowitz, followed by Stav Shaffir, who defected from Israel's other left-wing party, Labour.
Ms Shaffir, a leading campaigner for social issues, came in second place in the Labour primaries earlier this month but was angry that the new Labour leader, Amir Peretz, refused to agree to a merger of all the parties on the left.
In a joint news conference of the three leaders, Mr Horowitz said the Israeli left was becoming a strong and significant force again.
"We are embarking on a path that in a month and a half will lead to replacing the leadership and to a social change," he said. "We will defend Israel from the racism, corruption, occupation and religious coercion of the Netanyahu government."
With a minimum threshold of four seats required for a party to enter the 120-seat Knesset, mergers of smaller parties are common.
A poll on Thursday night showed the new list winning 10 seats.
Labour dropped two seats to five, as did the centre-left Blue and White, the main challenger to Mr Netanyahu's Likud, which received 27 seats, compared with 29 for Likud.
The right/religious bloc leads the centre-left bloc by 57 to 53 and Avigdor Lieberman’s Yisrael Beiteinu remains the linchpin with a projected 10 seats. Mr Lieberman, who describes himself as right-wing and secular, has vowed that he will not join a Netanyahu-led government.
In order to pave the way for Thursday’s merger, Mr Barak earlier this week issued a public apology to the families of 13 Arab citizens killed by police in protests in 2000 at the start of the second Palestinian intifada uprising, when he was prime minister.
Without such an apology Meretz Knesset member Issawi Freij said he would oppose the merger with Barak.
Responding to the news of the merger, Mr Netanyahu, who on Saturday became Israel’s longest-serving prime minister, tweeted: “I won’t get involved in how the left splits its votes.”
The new party still hopes to woo other leading figures, including former foreign minister Tzipi Livni.