India's main opposition Congress party appointed Mallikarjun Kharge as its leader on Wednesday.

The 80-year-old is the first Congress leader not from the Gandhi dynasty in 24 years, as the party looks to reverse its slow decline.

Former minister Kharge was elected by members to replace Sonia Gandhi as president of the once-mighty party that helped win India's independence 75 years ago, media reports said.

Congress governed India for decades after independence from Britain in 1947 but is now a shadow of its former self, discredited and crushed under the electoral juggernaut of Prime Minister Narendra Modi's Bharatiya Janata Party (BJP).

The Gandhi family is not related to India's independence icon Mahatma Gandhi but descended from the country's first prime minister Jawaharlal Nehru.

Nehru was the father of Prime Minister Indira Gandhi, assassinated in 1984. She was the mother of Rajiv Gandhi, killed by a suicide bomber in 1991.

The BJP thrashed Congress in the last two elections, with Modi deriding Rahul Gandhi – son of Rajiv and Sonia – as an out-of-touch princeling and playboy.

After the latest defeat in 2019, he resigned as party president and handed the reins back to his Italian-born mother Sonia, now 75.

Kharge, a veteran politician from southern Karnataka state, is widely believed to have the backing of both Sonia and Rahul.

He now faces the mammoth challenge of winning the next national election due in 2024 and three state elections next year, including in his home state where he personally has won 11 of the dozen elections he has contested during his long career in the Congress party.

Kharge faced off against Shashi Tharoor, 66, who campaigned for "change" in the leadership.