Rahul Gandhi, whose father, grandmother and great-grandfather all served as prime minister, was the centre-left party's front man in the last general election. But his 70-year-old mother Sonia remains its president and still calls the shots.

She has not publicly announced a decision to stand down as Congress president, but party official Mullappally Ramachandran said after a meeting of senior leaders on Monday that an election would be held next month.

The announcement followed months of speculation that the 47-year-old scion of the Gandhi dynasty would soon take over from his mother.

Rahul Gandhi was elected vice-president of the Congress party in 2013 and has long been his mother's presumed successor.

He was strongly criticised for a lacklustre campaign that led to a defeat by Narendra Modi's Bharatiya Janata Party in the 2014 general election.

But few inside the party, which has since suffered a series of state election defeats, have been willing to publicly criticise the family that has been at its helm for generations.

Rahul has long had the reputation of a reluctant leader, although some analysts say he has displayed greater political acumen since the 2014 election defeat.

“Earlier, he was too young and didn't have a lot of experience, so he used to make mistakes sometimes. But now, he has become more seasoned,” veteran party leader Virbhadra Singh told AFP ahead of Monday's announcement.

Congress has ruled India for most of the period since independence in 1947 and has almost always been led by the Nehru-Gandhi clan, beginning with the first prime minister Jawaharlal Nehru.

On Monday, the party set a December 4 deadline for nominations for president and said any vote would be held on December 16.

It held its last leadership election in 2010, when Sonia Gandhi stood unopposed.