"Contrast the mood at Moody's with the mood of the people. While you bask under their upgrade worry about livelihood millions have lost," Mr Sibal said in a tweet.
"Moody's talks about sunshine tomorrow. We are worried about the dark clouds today," he said.
Maintaining that the upgrading was based on New Delhi's "wide-ranging programme of economic and institutional reforms", Moody's simultaneously changed the outlook for the country's rating to stable from positive and upgraded India's local and foreign currency issuer rating to Baa2 from Baa3.
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