JERUSALEM - A confidant of Prime Minister Ehud Olmert says the Israeli leader will step down "immediately" after his party chooses a successor this month.

The comment Thursday shoots down speculation that Olmert would try to linger in office for months.

The Olmert confidant says the Israeli leader will formally resign "immediately following the primary." He spoke on condition of anonymity because the Israeli leader has not made his plans public.

Olmert has already announced plans to resign in order to battle a corruption investigation. But he has been unclear when he would actually step aside.

Olmert's Kadima Party is scheduled to hold a primary next Wednesday. The party could hold a runoff if no candidate receives 40 percent of the vote.