By constitutional requirement, elections to the Lok Sabha must be held at an interval of five years or whenever parliament is dissolved by the president. The previous election, to the 15th Lok Sabha, was conducted in April–May 2009, and its term will naturally expire on 31 May 2014. The election is being organised and conducted by the Election Commission of India (ECI) and was held in multiple phases, to better handle the large electoral base and security concerns.