2015 Mexican legislative election
Legislative elections were held in Mexico on 7 June 2015, alongside municipal elections. Background. Traditionally elections had taken place on the first Sunday of July, but in 2015 were set to the first Sunday of June. Electoral system. The 500 members of the Chamber of Deputies were elected by two methods; 300 were elected in single-member constituencies, and 200 by proportional representation in a single nationwide constituency. Constitutional reforms in 2014 led to the creation of the National Electoral Institute, replacing the Federal Electoral Institute.