While BJP steered clear of the controversy, Congress waded into it with an attack saying it reflected the "fascist mentality" of BJP.
"Mr Chandan Mitra may not know that the Bharat Ratna was given to me by the BJP-led government and was handed to me by Atal Bihari Vajpayee. If Mr Vajpayee wants me to return it, I will certainly return it," Amartya Sen.
He said it was unfortunate that such a demand had come forth and termed it as a "personal" view of Mitra.
"To get into a political debate and somebody takes a view which seems to me is rather unfair...to all the people as well....I think it is unfortunate....It is so unproductive actually," Sen said.
He added that during the BJP-led NDA government, he has had a lot of discussion with leaders like L K Advani, Yashwant Sinha, Jaswant Singh and Arun Jaitley.
Demanding that Sen be stripped of his Bharat Ratna, Mitra had said he was not even a voter in India and wondered whether a Bharat Ratna awardee should speak for or against any party or a leader.
Information and Broadcasting Minister Manish Tewari hit out at the BJP for its attack on Sen, who had raised the heckles of the saffron party saying he did not want to see Narendra Modi as prime minister since he did not have secular credentials. The prominent economist had also criticised Modi's model of governance saying he did not approve of it.
Tewari said it was "regrettable" that BJP resorted not only to the "ignominy" of asking Sen to return the Bharat Ratna, something that happened for the first time, but some of its spokespersons also sought return of his Nobel prize.
"What kind of mentality is this. What is this if not fascism. That either you are with us or against us and if you are against us, return the Bharat Ratna. What wrong Amartya Sen has done Does the BJP believe in the freedom of expression. This is a big blow to the right to express, write and speak," Tewari said.
He said while Gujarat Chief Minister gave statements daily and the party defends its right to speak, "they think the voice of others should be muzzled".
Asked if Sen should be stripped of his Bharat Ratna as sought by Mitra, HRD Minister Shashi Tharoor said, "the question does not arise".
Asked about the controversy, Home Minister Sushilkumar Shinde said, "they should have not said like this." He added that whatever Sen has said about Modi should be correct as he a noted economist.
"Amartya Sen doesn't want Modi as PM, rates him below Nitish. For this sin BJP wants to strip his Bharat Ratna. Isn't it height of intolerance," Congress general secretary Shakeel Ahmed said on twitter.
Senior BJP leader Murli Manohar Joshi, however, steered clear of the controversy over Mitra's demand, saying, "this is his personal opinion".
Another party spokesperson Nirmala Sitharaman said, "Bharat Ratna debate is unfortunate. BJP is not a part of it. Views expressed by members can only be construed as their personal opinion."
JD-U leader K C Tyagi said the BJP demand only reinforces the total demise of the Vajpayee-Advani era based on tolerance, flexibility and accommodation of dissenting views.
"It's a crude attempt to stifle intellectual dissent which is the inherent right of any self respecting Indian. It represents the new personality driven cult of an intolerant India," he said in a statement.
Amartya Sen was speaking to Times Now