Mumbai Shiv Sena MLA Pratap Sarnaik on Saturday said the Bharatiya Janata Party (BJP) should give a written assurance that both alliance parties will have a chance to run the government according to the 50-50 formula "promised" by Union Home Minister Amit Shah during the Lok Sabha elections.

"In our meeting, it was decided like Amit Shah had promised 50-50 formula before Lok Sabha polls. So, both allies should get a chance to run the government for 2.5-2.5 years and Shiv Sena should also have the chief minister's post. Uddhav ji should get this assurance in writing from BJP," Sarnaik, Shiv Sena MLA from Thane told reporters.