[5][7] Initially its main support came from the Syrian Christians and the Nair community of southern Kerala.

[5][6] Fifteen rebel Congress Members of the Legislative Assembly subsequently supported a successful no confidence motion on the Sankar Ministry.

[5] K. M. George, R. Balakrishna Pillai and other leaders backed by the Syro-Malabar Catholic Church and the Nair Service Society leader Mannathu Padmanabhan, formed the "Kerala Congress" at Kottayam Thirunakkara Ground on 9th October 1964.

[6][5] K. M. Mani, with the Congress alliance, served as the Home Minister in the later K. Karunakaran and A. K. Antony led ministries (replaced in between by P. J.

[6][5] However, Splinter fractions of R. Balakrishna Pillai and K. M. Mani merged with parent Kerala Congress led by P. J. Joseph in 1985.

P. C. Thomas did not support this merger and made his own fraction called Kerala Congress (Anti-merger Group).

[9] In 2016, after a long legal battle P. C. Thomas received approval to use the name as bracket less Kerala Congress party.

P. C. Thomas contested from Kottayam Lok Sabha constituency for NDA[10] on 2019 Indian general election In October 2020, it was reported that P. C. Thomas was leaving NDA and was likely to join the United Democratic Front (UDF).