After the 1986 elections, Sadiq formed a coalition government comprising the Umma Party (which he led); the National Islamic Front (led by his brother-in-law, Hassan Al-Turabi); the Democratic Unionist Party (led by Mohammed Uthman al-Mirghani al-Khatim); and four small Southern parties. However, this coalition proved to be unstable, preventing Sadiq from delivering on his promises to end the Second Sudanese Civil War and fix the ongoing economic crisis. On 30 June 1989, his government was overthrown in a coup led by Brigadier Omar al-Bashir. The post of Prime Minister of Sudan was then abolished.