TEL AVIV – Former IDF chief of staff Benny Gantz turned down an offer from Zionist Union chief Avi Gabbay to take over as head of the opposition, Israeli media reported Tuesday.

In an interview Monday with Channel 10, Gabbay said he would not give up his place as head of the Zionist Union. However, a later report on the channel said that Gantz had declined an offer made by Gabbay to head the ticket. The Zionist Union’s main factions are Labor, which Gabbay heads, and Tzipi Livni’s Hatnua.

Recent polls have shown that an alliance between Gantz and the center-left bloc, represented either by Zionist Union or Yesh Atid, could present a real challenge to the ruling Likud faction, which is predicted to win around 30 seats.

Gantz is rumored to be forming a new party that would be “moderate and responsible centrist” with the word “left” conspicuously omitted, sources told Haaretz.

Livni on Tuesday called for the opposition to join together against Netanyahu.

“All of us need to put our ego aside for the shared goal, which is a political revolution,” Livni, who acts as opposition leader in the Knesset, said at an event held by the Israel Democracy Institute and the Interdisciplinary Center.

“The only way to win is to join forces,” she added.

Former defense minister Moshe Ya’alon announced Tuesday that he will also establish a new party, while former prime minister Ehud Barak said he may return to politics if there is a strong enough center-left challenger to Netanyahu.

Early elections are set for April 9.