The leader who did not wish to be named said: "After Soniaji (Gandhi) took over the leadership on August 10, she was upfront regarding issues related to the states going to the elections this year and early next year.
"Sonia Gandhi wants the house in order ahead of the elections," he added.
Assembly elections in Maharashtra, Haryana and Jharkhand are due later this year while Delhi will go the polls early next year.
The leader said Gandhi had had several rounds of meetings with senior leaders since August 15 to decide on a new unit chief in Haryana.
"And a decision on the new state unit chief is likely to be announced in two to three days," the source said.
Due to unending differences between Tanwar and former Haryana Chief Minister Bhupinder Singh Hooda, the party may replace the former with a new leader, the leader said.
On August 18, Hooda, while addressing a rally in Rohtak, came out in support of the Modi government's move to axe Article 370 of the Constitution.
Hooda also announced a 25-member panel to decide the party's future in the state, in a signal to the Congress leadership to hand over the party's reins in the state to him, failing which he would go his own way.
Speculations were rife that Hooda, a two-time CHief Minister, and his son Deepender Singh Hooda, a former MP, might quit the Congress after they said they were sidelined by the party high command.
On August 17, a day before the Rohtak rally, Hooda had a closed-door meeting with Congress leaders in New Delhi during which they tried to convince him not to take any hasty decision to quit the party as it had always accorded him the due importance.
In the October 2014 polls, the BJP improved its 2009 tally of four to 47, followed by the INLD with 19 legislators and the Congress coming third with 15 seats.
Two seats went to the Haryana Janhit Congress (HJC), and one each to the Shiromani Akali Dal (SAD) and the Bahujan Samaj Party (BSP). Five Independents were also elected.
( With inputs from IANS )