"The DMK should put more pressure on the Centre. They should pull out if necessary until the project comes to a halt," S P Udayakumar, Convenor of the People's Movement against Nuclear Energy told PTI over phone.
They did not pull out during the Lankan Tamils issue, he said, adding, the party had now an "opportunity to show their solidarity" with them.
Welcoming the state government's stand on the issue, he said, "We are happy that they are with us but we want everyone's support in this."
Tamil Nadu Chief Minister Jayalalithaa had blamed the Centre's "inaction" for the stalemate on the KNPP issue.
Asked about Atomic Energy Commission Chairman Srikumar Banerjee's recent observation that the Koodankulam plant will be commissioned in November, he said, "That is just to mislead us."
After suspending their stir for two days in view of Tamil Nadu civic polls, about 100 persons had resumed their relay fast near the KNPP site in Tirunelveli on Tuesday to protest against the Koodankulam nuclear power plant.