Israel’s ruling coalition could be under threat depending on the result of the Labour party leadership battle.
The current Defence Minister, and leader of the Labour Party, Amir Peretz, cast his vote in Sderot, his hometown, as more Hamas rockets were fired from Gaza.
But Peretz was tainted by last year’s war in Lebanon and it is thought he will lose the leadership.
One possible winner is Ehud Barak, the former Prime Minister, who pursued peace, albeit unsuccessfully, with the Palestinians.
He could face a run off with Ami Ayalon, an ex-Admiral and head of Israel’s Shin Bet secret service.
Both have said they would work to oust the discredited Prime Minister Ehud Olmert and might quit the coalition if he refused to resign.
Polls suggest no candidate will win an outright majority in the first round of voting, but a run-off could see Ayalon the victor.
It would be bad timing for a fracture in the ruling coalition as Israel battles the increased Hamas insurgency in Gaza.
The military said ongoing rocket attacks on Monday caused no casualties. But a man was killed by flying shrapnel in Sderot on Sunday, when a rocket hit his car.
He was the second Israeli fatality in a surge of cross border fighting over the past two weeks.
Israel’s retaliation was immediate. Fresh airstrikes targeted Hamas positions in the Gaza strip overnight.
About 40 people have been killed in Gaza overall in ten days of air strikes, aimed at stopping the rocket attacks.