Stunned by an early morning coup in which the BJP's Devendra Fadnavis took oath as Maharashtra chief minister, the Shiv Sena said it was "stabbed in the back" by Ajit Pawar of the Nationalist Congress Party (NCP), who was sworn in as Deputy Chief Minister.
Ajit Pawar, the nephew of NCP chief Sharad Pawar, had been present in meetings to form a coalition of the Shiv Sena, NCP and Congress till yesterday.
"This has been nothing but a stab in the back of the people of Maharashtra," said Shiv Sena leader Sanjay Raut. "Ajit Pawar was there in the meeting yesterday, but late last night his phone was suddenly switched off and even the NCP don't exactly know what happened suddenly."
Sharad Pawar has claimed that Ajit Pawar's move was his "personal decision" and not that of the NCP. However, the entire NCP is believed to have backed the Devendra Fadnavis government.
"I am certain that the decision taken by Ajit Pawar has nothing to do with Sharad Pawar. What Ajit Pawar has done will never be forgiven by Chhatrapati Shivaji and the people of Maharashtra," said Mr Raut.
He said Shiv Sena chief Uddhav Thackeray and Sharad Pawar would meet and address a press conference this afternoon.
The Shiv Sena, which was hoping to lead a coalition with the NCP and the ideologically opposite Congress after breaking up with three-decade-old ally BJP, has emerged as the worst-hit in the shocking turn of events.
Last night, after the first meeting of the Shiv Sena, NCP and the Congress, Sharad Pawar had said there was a consensus on Sena chief Uddhav Thackeray becoming chief minister.
In a stunning twist this morning, President's Rule was revoked at 5.47 am and Devendra Fadnavis took oath as chief minister for the second time, shortly afterwards.
Mr Raut said he had found Ajit Pawar's body language "suspicious".
"Till 9 pm this mahashay (person) was sitting with us and participating in discussions. He suddenly vanished. He was not looking us in the eyes while talking, we could tell something was amiss," said the Sena MP.