More than two dozen opposition parties said on Tuesday that they had joined hands to form an alliance called "INDIA" to take on Prime Minister Narendra Modi's ruling Bharatiya Janata Party (BJP) in parliamentary elections next year.
The decision was announced at the end of a two-day meeting of 26 parties in Bengaluru.
Congress President Mallikarjun Kharge said INDIA stood for "Indian National Developmental Inclusive Alliance".