BJP MP Subramanian Swamy has called economist Amartya Sen a "traitor", adding that he was conferred the Bharat Ratna "just because he was Left-wing and Sonia Gandhi pressed for it". Sen, who received the Nobel Prize for Economic Sciences in 1998, was awarded Bharat Ratna, India's highest civilian honour, by former PM AB Vajpayee-led NDA government in 1999.