"Chidambaram is a good human being but the BJP is needlessly trying to cast aspersion on the character of the Home Minister," he told reporters in reply to a question.
The BJP was indulging in "dirty politics" by targeting Chidambaran after the Madras High Court refused to dismiss a petition challenging his election to the Lok Sabha three years ago, Prasad alleged.
He said Chidambaram may have suffered a setback in the high court, but he has the option to challenge the order in the apex court.
Prasad alleged that the BJP was desperate to regain power at the Centre by all means and the RSS has virtually declared Gujarat Chief Minister Narendra Modi as the saffron party's prime ministerial candidate for the 2014 parliamentary elections.