Posters welcoming the young leaders were seen outside the Congress office earlier today.
Former student leader Kanhaiya Kumar and Gujarat Dalit leader Jignesh Mevani today joined the Congress. They were inducted at the All India Congress Committee headquarters in New Delhi in the presence of party leader Rahul Gandhi.
Mr Kumar was earlier with the Communist Party of India (CPI) which he joined ahead of the 2019 general election. He then contested from his hometown Begusarai in Bihar against the BJP's Giriraj Singh of the BJP but failed to win.
"Begusarai rejected Kanhiya Kumar's ideology earlier. Now he's changing his ideology and party for political ambition but public doesn't vote for anyone's political ambition. He's going to a party that has been rejected by Bihar and is a sinking boat now," Bihar Minister Mangal Pandey told ANI, reacting to Mr Kanhaiya's latest move.
Posters welcoming him to the party were put up outside the Congress office hours ahead of his switch. He reportedly met Mr Gandhi twice recently over two weeks. He also met Priyanka Gandhi Vadra.
A former president of the JNU Students' Union, Mr Kumar was jailed over alleged "anti-national slogans" raised at an event in 2016 to mark the death anniversary of Parliament attack mastermind Afzal Guru.
A legislator representing Gujarat's Vadgam constituency, Mr Mevani is key to the Congress's poll arithmetic ahead of next year's Assembly election in that state.
He is a lawyer and former journalist and is entering the Congress at a time when the party is reaching out to the Scheduled Caste community -- it recently replaced Amarinder Singh as Punjab Chief Minister with Charanjit Singh Channi, a Dalit.