Nitin Chaturvedi, son of senior Congress leader and former MP Satyavrat Chaturvedi, filed nomination as a Samajwadi Party (SP) candidate Thursday from Rajnagar in Bundelkhand region of Madhya Pradesh.
Assembly elections will be held in the BJP-ruled state on November 28.
Nitin Chaturvedi filed his papers in the presence of his father and a group of supporters.
Satyavrata Chaturvedi, a former Congress national spokesperson, said he himself was still with the Congress.
"I am still a Congress member. Congress has been repeating the same mistake (of ignoring his son) for 15 years. Doing injustice is sin, and tolerating injustice is equally sinful. So my son took the decision to go to the people's court," he said.
"It was Nitin's own decision to contest on SP ticket. He is adult and a father of two children, so he can take decision on his own. I will help him as much as I can," Satyavrata Chaturvedi added.
Nitin Chaturvedi alleged that the Congress has ignored its ground-level workers.
The party has fielded Vikram Singh Natiraja, a three-time MLA, from this seat.
Defending the decision to give ticket to Natiraja, Congress spokesperson Pankaj Chaturvedi cited his record.
"Natiraja is a three-time MLA from here. He won two consecutive elections, in 2008 and 2013, on Congress ticket. He was elected as MLA on SP's ticket in 2003. How can Congress ignore ground reports," he said.