Congress leader Digvijaya Singh will file nomination for the post of the party president for which election is scheduled to be held on October 17.
He took his nomination form from the party's Central Election Authority (CEA) earlier in the day.
Sources close to Singh on Wednesday said the decision to contest the polls is his personal one, adding that nobody from the Gandhi family asked him to do so.
The former Madhya Pradesh Chief Minister may file the nomination by September 30, which is the last date for nominations.
Congress' initial plan was to field Chief Minister Ashok Gehlot for the top party post, but the high-octane drama in Rajasthan has miffed the Gandhis. Gehlot is in Delhi and has met Mukul Wasnik, but the suspense over his candidature continues.
Sources in the know of things said, "Gehlot has not been ruled out from the race yet".
Congress treasurer Pawan Kumar Bansal has taken a nomination form from the CEA. On his part, Bansal said he is only a proposer and not a candidate.
CEA chairman Madhusudan Mistry on Tuesday had said: "Till now, Shashi Tharoor and Pawan Bansal have taken nomination forms from the CEA."
Senior Congress leader Kamal Nath whose name had also come up and had met Congress interim President Sonia Gandhi on Monday, said that he did not want to become the party chief, and wants to continue to work for the party in Madhya Pradesh.
The drama in Rajasthan has made the Congress leadership think about a 'Plan B' for the top party post for which Gehlot was being seen as a contender. However, the open defiance by his MLAs loyal to him brought him under a cloud.