DMK leader MK Stalin on Wednesday said a Congress-DMK alliance at the Centre had always proved successful "whenever the country faced a threat".
"Whenever the country faced a threat, the Congress and the DMK alliance has been formed and was also successful", he said, but did not elaborate.
He was reacting to Prime Minister Narendra Modi's opportunism barb at an NDA rally at Tamil Nadu's Kanchipuram earlier in the day near Chennai.
PM Modi had said that if there was one party that has abused Article 356 again and again, it was the Congress.
Even the DMK had become a victim, PM Modi said, and hit out at the Dravidian party for joining forces with Congress, saying "opportunism has prevailed over values".
Mr Stalin, addressing a DMK meet in Virudhunagar, expressed confidence that Congress president Rahul Gandhi would head the next government at the Centre.
He said the BJP alliance in Tamil Nadu was opportunistic and was formed due to "coercion".
"Which front will win... Is the Congress front that is going to save the country? Or the opportunistic alliance?" he asked.