Nuri al-Maliki was due to drop his bid to remain Iraq's prime minister in a joint televised appearance with his designated successor, his spokesman said Thursday.
"Maliki will withdraw the complaint against the president and will back the prime minister designate," Ali Mussawi told AFP, referring to a lawsuit the outgoing premier had vowed to file.
President Fuad Masum on Monday tasked Haidar al-Abadi, a member of Maliki's Dawa party, with forming a new government, a move the two-term premier said was a violation of the constitution.
Tehran and Washington, the two main foreign power brokers in Iraq, came out in support of Abadi, and he was dealt another major blow when the office of Iraq's top Shiite cleric released a letter in which he called for Maliki to go.
Maliki went from relatively unknown exile to become a powerful premier who has been widely criticised for authoritarian tendencies.
His tenure will end with Iraq facing a major crisis to which his policies have contributed.
Jihadist-led militants are in control of major areas of five Iraqi provinces, after launching an offensive in June that swept aside security forces, of which he is the commander-in-chief.