Sharad Pawar said BJP has tried unconstitutional ways to gain power in Goa and some other states.
A day before the Supreme Court rules on a floor test for Maharashtra government led by Devendra Fadnavis whose swearing-in has been challenged by Shiv Sena-NCP-Congress combine, the three parties paraded 162 MLAs in a show of strength in Mumbai.
At the event, the MLAs took an oath at not to fall prey to any inducements by BJP.
NCP MLA Dhananjay Munde said 162 MLAs of the three parties were present at the event, held at a luxury hotel on Monday evening.
NCP chief Sharad Pawar told the gathering of MLAs that he would personally ensure that none of them loses membership for voting against the BJP during floor test in the Assembly.
Sharad Pawar addressed a joint meeting of the MLAs of ''Maha Vikas Aghadi'' comprising the Shiv Sena, NCP and Congress at the five-star hotel.
The NCP chief said BJP has tried unconstitutional ways to gain power in Goa and some other states.
"Maharashtra is not Goa and it is time to teach them a lesson," Mr Pawar said.
"A misinformation is being spread that Ajit Pawar is the NCP''s legislature party leader who would issue a whip to all (NCP) MLAs to vote for the BJP (in floor test). It is being said that whoever defies the whip would lose his membership of the House," Mr Pawar said.
The NCP chief added that he had consulted several constitutional and legal experts and also gone through previous instances on the issue of technicalities.
"I have come to the conclusion that Ajit Pawar, who is removed from his position (as the NCP legislature party leader for joining hands with the BJP in forming a government), has no legal right to issue a whip to MLAs," Mr Pawar said.
"I personally take the responsibility that your membership of the House will not become null and void. People who have acquired power illegally have to be removed now," Mr Pawar said apparently referring to the BJP.
Shiv Sena chief Uddhav Thackeray, speaking at the event, asked the BJP to "make way" for the Sena-NCP-Congress alliance to rule Maharashtra.
Those present were at the parade were Congress leader Ashok Chavan, who said, "We are more than 162, not just 162.
We all will be a part of the government. I thank Sonia Gandhi who allowed for this alliance to stop BJP."
"The governor should invite us to form government," he said.