Under Article 324 of the Constitution the superintendence, direction and control of the preparation of the electoral rolls for, and the conduct of, all elections to the Parliament and to the Legislative Assembly of every State and of the elections to the offices of President & Vice-President, are vested in the Election Commission which consists of the Chief Election Commissioner and Election Commissioners. The powers vested in the Election Commission under Article 324 of the Constitution are supplemented further by Acts of Parliament, namely the Representation of the People Act, 1950, the Representation of the People Act, 1951, the Presidential and Vice Presidential Act, 1952, etc.At the state level, the election work is supervised subject to the superintendence, direction and control of the Election Commission, by the Chief Electoral Officer (appointed by the Election Commission) and the officers and staff working under him.

The Chief Electoral Officer is normally appointed from the Indian Administrative Service. The district electoral machinery comprises the District Election Officers (DEOs) [generally the Collectors or District Magistrates; in the case of Chennai, the Commissioner of the Corporation], Electoral Registration Officers (EROs) & AEROs (for preparation & maintenance of electoral rolls) (generally officers in the level of Sub-Divisional Magistrates), Returning Officers (ROs) & AROs (for conduct of elections) and other officials [like Personal Assistant (Elections) to the Collectors, Presiding and Polling officers] appointed for the conduct of elections. The Office of the Chief Electoral Officer was set up in Tamil Nadu before the first general elections in independent India in 1952, with reference to the provisions of Section 13A of the Representation of People Act, 1950, for carrying out the following