He had defeated Minister of State for Home Praful Patel in the 2012 assembly elections.
Chawda submitted his resignation to Speaker Vajubhai Vala on Friday. This brings the Congress' strength down to 55 in the House. The party had bagged 60 seats out of 182 in 2012.
Earlier, Somnath MLA Jasa Barad had resigned from the Saurashtra region to join the BJP. Barad had quit the BJP in 1995 along with senior leader Shankersinh Vaghela who formed his own outfit called Rashtriya Janata Party that later merged with the Congress.
Gordhan Jhadaphia, who later quit the BJP, is in talks with Modi. Jhadaphia is a veteran Vishwa Hindu Parishad leader. Earlier, rebel BJP veteran, Keshubhai Patel,too had resigned as an MLA and quit politics.