Six-time legislator Dilip Sopal on Tuesday resigned as NCP MLA and is set to join the Shiv Sena on Wednesday.
Assembly Speaker Haribhau Bagde accepted Sopal's resignation, a Vidhan Bhawan official said.
On Monday, Sopal, NCP MLA from Barshi in Solapur district, had formally announced his decision to quit the Sharad Pawar-led party.
Sopal is expected to join the Shiv Sena in the presence of that party's chief Uddhav Thackeray at a function in Mumbai on Wednesday.
There is speculation that former NCP MP Dr Padamsinh Patil, who has been with the party since its formation in 1999, and his son Rana Jagjitsinh Patil may also be on their way out.