Ganpat Gaikwad's party is in alliance with Mr Shinde's Shiv Sena in Maharashtra.
Maharashtra BJP legislator Ganpat Gaikwad has alleged that he fired at an ally Shiv Sena leader in self-defence and he has "no regrets" since they were beating his son inside the police station. He has been arrested.
Mahesh Gaikwad, who belongs to Chief Minister Eknath Shinde's faction, and another supporter were injured in the firing after an argument over a land dispute. The incident occurred last night in Ulhasnagar, which comes under Kalyan parliamentary segment.
"Yes, I shot (him) myself. I have no regrets. If my son is being beaten in front of the police inside the police station, what will I do," he told a news channel.
Ganpat Gaikwad, whose party is in alliance with Mr Shinde's Shiv Sena in Maharashtra, also came down heavily on the Chief Minister and said he is "trying to create a kingdom of criminals in Maharashtra".
"Shinde saheb betrayed Uddhav (Thackeray) saheb, he will also betray BJP. He owes me crores of rupees. Shinde should resign if Maharashtra is to be well-managed. This is my humble request to Devendra Fadnavis (Deputy Chief Minister) and Prime Minister Narendra Modi," reports quoted him as saying.
The Kalyan East MLA was referring to the revolt by Mr Shinde that brought down the Thackeray government in 2022.
He also accused the Chief Minister's son and MP Shrikant Shinde of putting up boards to grab credit for his works. "If Eknath Shinde is the Chief Minister, only criminals will be born in Maharashtra. He has made a good person like me a criminal today," he said.
The MLA said his son had gone to lodge a complaint at the police station, but the Sena leader's men started manhandling him, which prompted him to shoot at them. He claimed he fired five rounds in the police station.
The land dispute at the centre of the incident pertains to a plot that the MLA had bought 10 years ago. He claimed there were some legal issues but he won the case in the court, after which Mahesh Gaikward occupied it by force.
The police said Ganpat Gaikwad and two others have been arrested under attempt to murder charges. The injured Sena leader remains critical and on ventilator.
The incident has provided the Uddhav Thackeray faction with fresh ammunition to target the Maharashtra government over law and order.
"A BJP MLA opened fire inside the police station and the person who was shot is close to the Chief Minister and a former corporator. Both their parties are in power, so should we understand that these people have no fear of the law? Both engines of the state government have failed," said Uddhav faction spokesperson Anand Dubey.