Israel's attorney general has charged Prime Minister Benjamin Netanyahu with bribery, fraud and breach of trust in connection with three separate cases, the justice ministry says.
Mr Netanyahu is alleged to have accepted gifts from wealthy businessmen and dispensed favours to try to get more positive press coverage.
He has denied any wrongdoing and said he is the victim of a "witch hunt" by his left-wing opponents and the media.
He has insisted he will not resign and is not legally obliged to do so.
But the announcement comes amid a political stand-off in Israel following two inconclusive general elections in April and September.
On Wednesday, Mr Netanyahu's rival for the premiership, Benny Gantz, said he had been unable to command a majority in parliament and form a governing coalition.
President Reuven Rivlin had given him the opportunity to try and form a government after Mr Netanyahu failed to do so.
Mr Rivlin formally asked lawmakers on Thursday to agree on a candidate for prime minister within 21 days and avoid an unprecedented third election in a year.
What are the charges?
The attorney-general, Avichai Mandelblit, said in February that he intended to indict Mr Netanyahu in connection with three cases - known as Case 1000, Case 2000 and Case 3000 - pending final hearings that eventually took place last month.
- Case 1000: Mr Netanyahu has been charged with fraud and breach of trust in this case. Mr Netanyahu is alleged to have received various high-value benefits, including pink champagne and cigars, in return for favours for a wealthy friend. Mr Netanyahu has said they were tokens of friendship and that he did not act inappropriately in exchange for them. The friend similarly denies any wrongdoing.
- Case 2000: Mr Netanyahu faces charges of fraud and breach of trust in this case. He is alleged to have agreed a deal with the publisher of a major newspaper to promote legislation to weaken a rival daily in return for favourable coverage. Like the prime minister, the publisher denies any wrongdoing. Both men have said they did not intend to promote the matters discussed in their meetings, and the legislation was not passed.
- Case 4000: This is considered the most serious case because Mr Netanyahu has been charged with bribery in connection with it, as well as fraud and breach of trust. It is alleged that Mr Netanyahu promoted regulatory decisions that favoured a leading telecommunications company in return for favourable news coverage from one of its websites, as part of an agreement with the company's controlling shareholder. The prime minister has insisted experts supported the regulatory decisions and that he received nothing in return. The shareholder also denies wrongdoing.