Senior Shiv Sena (UBT) leader from Thane, Anita Birje, joined the Shiv Sena faction led by Chief Minister Eknath Shinde on Saturday night.
Shinde welcomed Birje into the party at a function attended by numerous party workers, with a significant presence of women.
Birje, who previously led the women's wing of Shiv Sena (UBT) in Thane, had been a close associate of the late Sena veteran Anand Dighe, who was also Shinde's political mentor.
Despite her long-standing loyalty to Dighe, Birje initially chose to stay with Uddhav Thackeray after the undivided Shiv Sena split in June 2022.