Mr Yadav's party the Rashtriya Janata Dal (RJD) hastened to clarify that it was not. Lalu Yadav, said RJD spokesperson Manoj Jha, meant that the Income Tax Department is the BJP's new ally. He was accusing the ruling party of using central agencies to settle political scores after tax officials conducted raids in a case that links Mr Yadav and his family to alleged benaami or proxy land deals worth hundreds of crores.
Mr Yadav followed up his tweet with another, less than an hour later, in which he said in Hindi, "Don't get so excited. The alliance is unbreakable. Now a process is on to bring together parties with similar views. I am not afraid of the BJP's government machinery and agencies."
There were questions on Twitter by then like, "Is JDU moving to BJP?"
Nitish Kumar, who is the chief of the Janata Dal United or JD(U) said on Monday that if the BJP or central government have evidence of Lalu Yadav's corruption, they should take action.
Mr Yadav and Mr Kumar, political rivals for years, partnered together in the last Bihar assembly election to defeat the BJP. For almost two decades before an acrimonious split, Mr Kumar's party was an ally of the BJP. Sushil Modi, the Bihar BJP leader who has furnished documents that he alleges prove corrupt land deals by Mr Yadav and his two sons who are ministers in the state, was Mr Kumar's deputy for years.
Mr Yadav has accused the BJP, which rules at the Centre, of a conspiracy to put him jail to scuttle a mega rally of anti-BJP parties that he has planned in August. In his aggressive tweets today he also said that his "voice will not be suppressed" and that he would continue fighting "fascist forces."
"Nitish is responsible for resurrection of Lalu who plundered & ruined Bihar & still patronising only to remain CM," Sushil Modi tweeted today, adding, "We knew he (Lalu Yadav) will go hiding behind Social justice,vendetta,backward,poor.But don't worry all these are now with BJP."