Former Israeli premier Ehud Barak announced the formation of a new political party Wednesday that will compete in the September elections and seek to end Prime Minister Benjamin Netanyahu's "corrupt" rule.
"We are creating a new party to put an end to Netanyahu's power," Barak, 77, told a Tel Aviv news conference.
Denouncing Netanyahu's "corrupt" practises, he said Israel had "never experienced such dark days".
The party's name would be revealed in "two weeks" at its official launch, he said.
A former armed forces chief of staff, Barak succeeded Netanyahu as prime minister in 1999 and served as defence minister under him from 2009 to 2013 before retiring from politics.
"I've known you for 50 years... it's the end of the road for you," said Barak, addressing Netanyahu, who he once commanded in an elite army unit.
Netanyahu, 69, is facing possible indictment for bribery, fraud and breach of trust in the months ahead and is reportedly seeking legislation that would result in him being granted immunity.
He is up for re-election on September 17 after failing to form a coalition government following snap polls in April.
Parliamentary speaker Yuli Edelstein said Tuesday he was considering cancelling the elections -- a proposal hailed by Netanyahu.
"I appreciate the efforts of Mr. Edelstein to try to avoid new elections," Netanyahu wrote Wednesday on Facebook.
His main challenger, former army chief Benny Gantz who heads the Blue and White centrist alliance, slammed the possibility of circumventing the September polls, saying "there is no turning back".
Gantz added that if there was a possibility of forming a unity government without Netanyahu, his party would consider it.