Supporters of Congress MLA from Bhor in Pune district, Sangram Thopte, staged a protest on Monday after he failed to find a berth in the newly-expanded Cabinet led by Chief Minister Uddhav Thackeray.
A party leader from Bhor said all the 20 corporators of the Congress have resigned in support of Sangram Thopte, son of former minister Anantrao Thopate.
They have submitted their resignation letters to party higher-ups in Mumbai, he said.
Sangram Thopte refused to comment.
Earlier in the day, 36 legislators sworn in as ministers.
Among them, 14 ministers belonged to the NCP, 12 to the Shiv Sena while 10 others are from the Congress.