The fifth legislative assembly election of Tamil Nadu was held in March 1971, resulting in a re-election victory for the Dravida Munnetra Kazhagam (DMK), which had first won under the leadership of C. N. Annadurai in 1967. The main opposition was the Indian National Congress (Organisation) led by K. Kamaraj, while the Indian National Congress (Indira) faction aligned with the DMK. This election marked the first victory for M. Karunanidhi as DMK leader, who assumed office as Chief Minister after Annadurai’s death. Karunanidhi, supported by M. G. Ramachandran (MGR) in a leadership dispute with V. R. Nedunchezhiyan, secured his position with MGR and Vai. Balasundaram’s instrumental backing.

This election also set a precedent in national politics, as the Indian National Congress (Indira)—led by Indira Gandhi—formed a coalition with the DMK. This agreement allowed the DMK to take all seats in the state legislature, while conceding half of Tamil Nadu's seats in the Lok Sabha to the Congress.

With a 48.58% vote share and 184 seats, DMK achieved the largest single-party vote and seat count in Tamil Nadu's electoral history. This remains the only instance where a DMK-led government in Tamil Nadu retained power, as all subsequent DMK administrations have been succeeded by rival coalitions.

The state government was dismissed in January 1976 during Emergency, citing non-cooperation with the central government, just before completing 5 years in office, and President's Rule was imposed. The next assembly elections were held in June 1977.

Background

The opposition party, Indian National Congress was heavily weakened due to a split that occurred in 1969. This led to the formation of Indian National Congress (Organisation) under K. Kamaraj, which was the major opposition in this election, while the Indian National Congress, supported the Dravida Munnetra Kazhagam. Indira Gandhi continued as Prime Minister with the support of Communist parties and DMK which had 25 seats in the Lok Sabha. It was during this time that the long-awaited Salem steel mill was approved. The ruling Congress party decided to dissolve the Lok Sabha and conduct early elections to use the popularity from Bangladesh War victory. Then Chief minister of Tamil nadu M. Karunanidhi also decided to dissolve the state assembly and face the elections in alliance with Indira's Congress one year before the end of his term.

This election marked the most recent instance in which the Tamil Nadu Legislative Assembly election was conducted in multiple phases, with polling held over three days, 1 March, 4 March, and 7 March.

Parties and alliances The Dravida Munnetra Kazhagam (DMK) formed a seven-party alliance known as the Left and Democratic Front (Progressive Front). This coalition was led by the DMK and included the Indian National Congress (Indira), Communist Party of India (CPI), Praja Socialist Party, All India Forward Bloc, Muslim League, and M. P. Sivagnanam's Tamil National Party. The Congress party, reliant on DMK votes in the Lok Sabha for its survival, had no influence over seating arrangements. The Indira Congress contested in nine out of 39 parliamentary constituencies but did not participate in legislative assembly contests. Indira Gandhi directed the Tamil Nadu Congress leader, C. Subramaniam, to accept this arrangement, signaling a shift in the party's focus away from Tamil Nadu as a Congress stronghold.

The opposition front was a coalition of Kamaraj led Indian National Congress (Organisation) (Congress (O)), which joined hands with rival Rajaji's Swatantara Party, Samyukta Socialist Party, the Tamil Nadu Toilers' Party, the Republican Party and the Coimbatore District Agriculturist Association in a bid to unseat the DMK government from power.

Seat Allotment DMK Front

colspan="8" Progressive Front Party Flag Symbol LeaderSeats M. Karunanidhi 201 203 M. P. Sivagnanam2 M. Kalyanasundaram10 P. K. Mookiah Thevar 9 Muhammed Ismail 7 4T. Venkata Reddy1 Total 234

INC(O) Front NOTE: Two Leaves was free election symbol before 1972. colspan="8" Democratic Front Party Flag Symbol Leader SeatsK. Kamaraj19420161 C. Rajagopalachari1910George Fernandes 21S. Andi Thevar1 Total 234

Voting and results

Results

Source: Election Commission of India

AlliancesPartyPopular VoteVote %Seats contestedSeats wonChangeProgressive FrontSeats: 205Seat Change: +26Popular Vote: 8,506,078 Popular Vote %: 54.30% 7,654,935 48.58% 203 184 47 364,803 2.32% 10 8 6 268,721 1.71% 9 7 6 147,985 0.94% 4 4 — 69,634 0.44% 2 2 1Democratic FrontSeats: 21Seat Change: -50Popular Vote: 6,016,530Popular Vote %: 38.18%Indian National Congress (Organisation) 5,513,894 34.99% 201 15 New Party 465,145 2.95% 19 6 14 37,491 0.24% 2 0 —OthersSeats: 8 Seat Change: Popular Vote: 1,234,193Popular Vote %: 7.52% 965,379 6.13% 256 8 Communist Party of India (Marxist) 259,298 1.65% 37 0 Total10 Political Parties15,756,801 — —234 —

Results by district

+DistrictSeatsDMK+INC(O)+OTHChengalpattu151500Madras12831North Arcot221912South Arcot212001Dharmapuri9711Salem171700Coimbatore252401Nilgiris3210Tiruchirapalli221930Thanjavur232111Madurai221930Ramanathapuram171601Tirunelveli191720Kanyakumari7160Total234205218

By Region +Alliance-wise ResultsRegionTotal SeatsDMK-led Progressive FrontINC(O)-led Democratic FrontOthersNorthern Tamil Nadu70Western Tamil Nadu54Southern Tamil Nadu65Central Tamil Nadu45

By constituency