 On 22 September 2010, the 12th general convention of the Nepali Congress elected him as party President.The Nepali Congress emerged as the largest party in the 2013 Constituent Assembly elections under Koirala's leadership.He was elected leader of the Nepali Congress Parliamentary party securing 105 out of 194 votes against former Prime Minister Sher Bahadur Deuba's 89 votes and on 10 February 2014 he was nominated as prime minister.