Israel's attorney general has announced plans to indict prime minister Benjamin Netanyahu on charges of breach of trust and bribery.

The move followed months of mounting pressure and comes just six weeks before closely contested elections considered a referendum on Mr Netanyahu's legacy.

The 69-year-old has entered uncharted territories as the first sitting Israeli Prime Minister put on notice for prosecution.

Charges can only be filed after a hearing, likely to be held after the April 9 elections, in which Mr Netanyahu can contest the allegations.

The claims concern three separate cases in which Mr Netanyahu is accused of accepting expensive gifts and conspiring for positive media coverages in exchange for political favors.