Premier Benjamin Netanyahu is expected to declare that early elections will be held less than four months from now, a move that would give him a referendum on his leadership that would help him fend off both Israeli and international critics.
Polls suggest his re-election chances are good.
Officials from his Likud Party said that Mr Netanyahu will announce that the vote will be held on September 4.
Mr Netanyahu's government - Israel's most stable in years - could have remained in power until 2013. But coalition partners are challenging him on an array of domestic issues, including the budget, drafting the ultra-Orthodox and pulling down unsanctioned settlement construction.
His Likud Party is expected to win at least one quarter of parliament's 120 seats to become the legislature's largest faction, which would position him to become prime minister for a third term. He first served in the late 1990s.
What the polls do not show is what kind of future government he might head. If voting breaks down as the surveys indicate, Mr Netanyahu might be able to put together a more centrist coalition than his current government, which takes a hard line on peacemaking with the Palestinians and has submitted Bills designed to punish groups that disagree with Israeli policy on issues like settlements and wartime conduct.
The prime minister signalled in December that he might move up the vote when he called a snap Likud leadership race, which he won.
Early elections talk heated up last week, but an announcement was put off as Mr Netanyahu mourned the death of his father.
Over the weekend, several Israeli commentators said a possible Israeli strike on Iran drove Mr Netanyahu's quest for early balloting.
They reasoned that holding the vote before the US presidential race in November would give Mr Netanyahu an opportunity to order an attack in September or October, at a time when president Barack Obama would be reluctant to criticise him publicly for fear of alienating the Jewish vote.