In a surprise development, former Bihar chief minister Lalu Prasad Yadav's elder son Tej Pratap Yadav on Thursday tweeted that he has resigned as mentor of the Rashtriya Janata Dal's (RJD) student wing.

The move, days ahead of the Lok Sabha polls, comes as a big jolt to the party. His resignation also comes days after the RJD announced its list of star campaigners ahead of the 2019 Lok Sabha polls. The list included Rabri Devi, Tejashwi Yadav and Tej Pratap Yadav, among others.

In the tweet, Tej Pratap also said that those who think that he is "immature" are actually the ones who are "naive". "I know who is struggling at what level," he wrote.

Lalu Prasad's family has been witness to sibling rivalry for some time now, especially Tej Pratap's simmering differences with his brother Tejashwi. Tejashwi has been declared as the political heir apparent of the RJD supremo. The fight had come out in the open when their sister Misa Bharti's name was missing from the RJD star campaigner's list.

Tej Pratap had, in January 2019, announced that Bharti would contest from the Patliputra Lok Sabha constituency, even before the party made an official announcement about seat allocations. RJD insiders were quoted as saying by The Asian Age that the party was planning to field one of Tejashwi's closest aides Bhai Virendra from Patliputra constituency.

Tejashwi was the one made deputy chief minister in 2015 when the RJD, Congress and Janata Dal (United) formed the government while Tej Pratap got the health ministry.

After this government collapsed, Tejashwi became the Leader of Opposition. “The question of Tejashwi taking the lead has been settled by none other than Lalu Yadav,” Manoj Jha, an RJD member in the Rajya Sabha, had earlier said.