He is the founder of the Indian National Congress (INC)-led United Democratic Front (UDF) coalition, which governed the state in the periods of 1982-87, 1991-96, 2001-06 and 2011-16; and currently is the main opposition in Kerala since 2016[update].

[12] In 1937, Karunakaran joined the flood relief camps that were conducted by V. R. Krishnan Ezhuthachan, C. Achutha Menon, R. M. Manakkalath and other leaders of Prajamandalam, an early freedom movement in Kochi.

[citation needed] Eventually, Karunakaran rose to the level of senior leader of the INTUC, which became one of the largest trade unions in India with over 33 million members.

[citation needed] After a career of both achievements and setbacks in his 30s and most of his 40s, K. Karunakaran was allotted a ticket to contest from a Communist stronghold, Thrissur's Mala constituency, considered a "safe seat" for the Left, in the 1965 Kerala Legislative Assembly Elections.

To the astonishment of most political observers, 47-year-old K. Karunakaran defeated the Communist candidate by more than 3000 votes, and went on to represent the constituency in seven successive elections: 1967, 1970, 1977, 1980, 1982, 1987, and 1991.The VIP pavilion in Jawaharlal Nehru Stadium in Kaloor, Kochi is named in his honour.

Karunakaran quickly adapted to the role with his dexterous and Machiavellian capabilities putting the EMS Namboodiripad ministry on its toes despite the massive majority it enjoyed in the assembly.

However, Karunakaran, always a master strategist bided his time and played a crucial role in the overthrow of the Namboodiripad ministry and the subsequent formation of a coalition with the new Chief Minister, C. Achutha Menon.

Although Karunakaran could have technically staked a claim for Chief Ministership in 1970, he chose not to do so, being aware of Achutha Menon's administrative capabilities and visionary ideas for the state.

However, he had to resign after one month following the controversies that emerged about the Rajan case[15] paving the way for his rival AK Antony to become Chief Minister.

Mohammad Koya all serving as Chief Ministers in the 5th legislative assembly from 1977 to 1979, eventually calling for the need for a fresh mandate from the public.

The tragic assassination of former Prime Minister Rajiv Gandhi, two days before polling was scheduled to take place completely changed the tide in Kerala.

He was returning from Aluva after attending multiple meetings in Njarakkal Legislative Constituency, where there were by-elections, and his car collided with a tree at Pallippuram near Thiruvananthapuram, causing him serious fractures in head, limbs and the sixth vertebrae of his spine.

After the accident, he was hospitalized in Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum and was unable to manage the finances and administration of the state government.

[17] This became a political crisis when the state government was managed by a kitchen cabinet of Karunakaran's son K. Muraleedharan and his trusted aide and Chief Secretary of the Indian Administrative Service, K.

[20] Meanwhile a revisionist (Malayalam: തിരുത്തൽവാദി, romanized: thiruthalvadi) group emerged within Karunakaran's INC faction led by G. Karthikeyan, Ramesh Chennithala and M. I. Shanavas against his authoritarian tendencies and proxy rule by his son.

[21] The situation intensified into an intra-party revolt when M. A. Kuttappan, nominated by the state INC as a Rajya Sabha nominee, was denied candidacy by party leadership, which Karunakaran had considerable influence over.

[22][24] Thereafter the dissidence in the party grew into a full-scale crisis, with the Antony faction threatening to withdraw their support from the government, and G. K. Moopanar arriving on behalf of P. V. Narasimha Rao to insist that Karunakaran resign.

His foray into national politics was much less successful with Karunakaran suffering a shock defeat in his maiden parliamentary outing from his stronghold of Thrissur by a wafer-thin margin of 1,480 votes.

Both Muraleedharan and Padmaja were defeated in Congress bastions by landslide margins, along with the other UDF candidates, tarnishing both Antony and Karunakaran in the process.

The subsequent resignation of Antony and the installation of Oommen Chandy as Chief Minister only increased tensions, leading to Karunakaran walking out of the Congress in 2005.

[15] A habeas corpus petition was filed by T. V. Eachara Warrier asking the state government to produce his son Rajan (a student of the Regional Engineering College, Calicut who had actively participated in protests against the Emergency) in court.

[30] Karunakaran was accused of involvement in the Palmolein Oil Import Scam, about which a case was pending before the Supreme Court at the time of his death.

He was forced to resign due to allegations that his subordinate, senior Indian Police Service officer Raman Srivastava, was involved in the ISRO espionage scandal.