Sen cast his vote Wednesday at Bolpur in West Bengal's Birbhum district, for the first time since the 2001 assembly polls.
"My reaction on Modi is well known, I don't think he is a good prime ministerial candidate. Obviously he is popular among some sections, particularly in the business community. But that does not mean he is my favourite candidate, indeed he is not," Sen told reporters after exercising his franchise at a booth on Vishwa Bharati University campus.
"So, I will like someone who is more secular and the minority communities like the Muslims or the Christians do not feel threatened by him. So that has to be one characteristic of a leader," said Sen, who has strongly opposed Modi and questioned his secular credentials.