JERUSALEM — With Prime Minister Benjamin Netanyahu’s political future on the line — and possibly Israel’s — members of his conservative Likud party voted Thursday on whether to stick with their scandal-scarred leader or replace him ahead of a general election in March.

Mr. Netanyahu, who was indicted last month on corruption charges including bribery, was widely expected to prevail over his challenger, Gideon Saar, a seasoned but less popular party veteran.

Early Friday, Mr. Netanyahu declared victory.

“A giant victory!” he said on Twitter just after midnight, before official results were in. “With the help of God and with your help, I will lead Likud to a great victory in the upcoming elections and we will continue to lead the country to unprecedented achievements,” he added.