With his exit, the strength of AINRC will come down to 14 in the 30-member assembly, prompting CPI to call for the resignation of Chief Minister N Rangasamy.
AINRC has the outside support of lone independent MLA V M C Sivakumar.
A three-time MLA from Tirbhuvani (Reserved) constituency, Angalane joined Congress, which he had deserted in 2011, in the presence of PCC President A Namassivayam and other senior leaders including former Union minister V Narayansamy.
Angalane told PTI he would quit the assembly membership in a day or two.
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He was elected to the assembly from Tirubhuvanai since 2001 in all the last three elections. After winning on Congress tickets in 2001 and 2006, he had joined AINRC floated by Rangasamy ahead of 2011 polls and retained the seat.
Reacting to the development, CPI here demanded the resignation of Rangasamy claiming that it has lost majority.
"The AINRC's strength has come down from 15 to 14 in the 30-member assembly. Rangasamy should not face the elections as Chief Minister," People's Welfare Front Covenor and CPI state Secretary R Viswanathan told reporters here.
Viswanathan also wanted Assembly Speaker V Sabapathy to suo moto disqualify Angalane as he had 'defected' to Congress.
In the present assembly, whose term is expiring in May, AINRC has 14 MLAs excluding Angalane, Congress seven, DMK two and AIADMK five members.
In the recent Rajya Sabha elections, AIADMK nominee was elected from the lone seat from Puducherry with the support of AINRC.