Communist Party of India-Marxist general secretary Prakash Karat [Images] on Wednesday said that he could consider accepting the post of Prime Minister under 'inevitable circumstances', even as he categorically ruled out supporting the Congress in forming the next government.

Though he claimed that he was not at all interested in the post of Prime Minister, Karat told media persons in Tirupati that he would think of it if there was no other option.

Regarding the Left parties support to the Congress post-polls, Karat outrightly ruled out any such possibility and said that a non-Congress, non-BJP grouping would emerge as the largest political set up to form the next government at the Centre.

The Left parties would not support Congress in forming the next government "under any circumstances", he said.

Congress would 'undoubtedly' not be in a position to form the next government and has now become all alone with allies deserting it. Regarding the BJP he said that the saffron party was not going to open its account in several states.

Karat, accompanied by TDP Chief N Chandrababu Naidu [Images], was in Tirupati to take part in the last leg of campaigning that came to a halt on Tuesday evening.