The Communist Party of India-Marxist on Saturday said it was in talks with the Congress and other parties within and outside the United Progressive Alliance on the names of possible presidential candidates while not ruling out the possibility of Lok Sabha Speaker Somnath Chatterjee being in the race.

"I don't know. The politburo has told us to explore all options. It depends on all parties to see who is the most suitable candidate," party general secretary Prakash Karat said when asked whether a Left nominee could be put up for the post of President.

Addressing a press conference after the two-day politburo meeting, he said many names were being suggested, but "as far as we are concerned, nobody is ruled in or ruled out. Left parties have set out the criteria, but not zeroed in on any name."

The Left criteria for a presidential nominee is that the person must have a political background and firm secular credentials. The future President must be able to exercise judgment to maintain balance between the Parliament, Executive and Judiciary.

Karat said there was "more or less" a general consensus among secular parties on this criteria.

Asked about Vice President Bhairon Singh Shekhawat's name being floated by the Bharatiya Janata Party, he said, "You decide whether he falls within the criteria."

He said subsequent to the meeting of the Left parties on the issue in Delhi last week, the CPI-M has held consultations with "parties within and outside the UPA, as also Congress."