Strengthening the Congress at the national level was essential to check the communal parties as well as extreme Left forces. This would require bringing back senior leaders who had left the Congress in different states. It was for the Congress leadership to initiate this process, Karunakaran told a press meet in Thiruvananthapuram.

Karunakaran, who joined the NCP a few months back after dissolving his Democratic Indira Congress (Karunakaran), said his genuine concern for the Congress need not be construed as a hint to return to the parent party he had served for long.

"We have not even thought about merger. It is not on the cards," he said, complaining that the statements he issued after his recent trip to Delhi were misreported or misinterpreted.

Considering the prevailing political context, it would not be easy to make the Congress strong by keeping out popular leaders and seniors like NCP supremo Sharad Pawar, he said.

Asked if he was suggesting that Sonia Gandhi should step down as the Congress leader, he said she had been accepted as the leader by her party and also made chairperson of the ruling coalition at the Centre.

"After all, I have also had a small role in bringing Sonia Gandhi to the leadership," he said, adding it was for her to decide whether to continue or not.