Speaking to reporters here, S P Udayakumar, heading the PMANE, said he would sue Minister of State in the PMO, V Narayanasamy and Prime Minister Manmohan Singh for their comments on foreign funding.
Mr Udayakumar said Mr Narayanasamy had responded to a recent legal notice issued by him for alleging that he had received Rs 1.5 crore from foreign sources.
"He (Narayanasamy) had denied that he had made any comments aimed at maligning me but he had linked me with a Swedish organisation in which my name figures in the expert panel. I am wondering if the Prime Minister had also made remarks in the same context," Mr Udayakumar said.
The PMANE convenor said he would also take legal action against Congress leader E V K S Elangovan who had claimed that he was convicted for drug peddling in the US.
"We condemn this anti-people attitude and request the Central government and the department of Atomic Energy to respect the feelings of the Tamil people and immediately close down the Plant," he said.
The Prime Minister in an interview to the 'Science' journal had criticised NGOs that received support from abroad for leading protests against the Plant.
On the state government appointed expert panel vouching for the safety of the Kudankulam nuclear plant, Mr Udayakumar said it was "unethical and unprofessional" to make such a statement even before the report was submitted to the government.
The commissioning of the Indo-Russian joint venture, originally scheduled for December last, has been delayed for several months following continuing protests against the Plant by the local population over safety concerns.
Talks initiated both by the Central and state governments with the agitators have failed to break the deadlock.