The Sudan People's Liberation Movement-in-Opposition, also known as the anti-governmental forces (AGF), is the main South Sudanese opposition political party and rebel group that split from the Sudan People's Liberation Movement in 2013, due to political tensions between President Salva Kiir and Vice President Riek Machar over leadership of the SPLM. Tensions grew between forces loyal to Kiir and Machar and South Sudan plunged into the South Sudanese Civil War.