Sinha was welcomed into the BJP by Jharkhand BJP Working President, Ravindra Kumar Ray, at the state party office in Ranchi, with Assam Chief Minister Himanta Biswa Sarma also present.
Expressing discontent with the Congress, Sinha told , "I dedicated 27 years to the party, but my efforts were unrecognised. Inspired by Prime Minister Narendra Modi, I have joined the BJP unconditionally and am ready to serve," adding that his decision was not driven by a desire for any position or ticket but by a sense of neglect within the Congress.
He said, “I did not demand a ticket for myself. My contention was that this is a traditional seat of the Congress, it should not have gone to the Jharkhand Mukti Morcha (JMM). Then I talked to my supporters and they advised me to leave the party, so I resigned."
Sinha alleged that the Congress party has surrendered to the JMM on all the seats in Jharkhand.
Jharkhand BJP Executive President and Joining Committee Chairman, Dr Ravindra Rai, praised Sinha’s decision, saying it was a crucial step for the party and the state's welfare.
Sarma added that Sinha's inclusion would strengthen the BJP’s state organisation.
Sinha had hoped to contest the Bhawanathpur seat in the upcoming elections. However, as part of the INDIA bloc seat-sharing arrangement, the seat was allocated to the JMM, which fielded Anant Pratap Dev.
In his resignation letter to Congress President Mallikarjun Kharge, Sinha expressed disappointment over repeated "insults" and feeling undervalued, adding, “There is a limit to tolerance.” With that, he announced his resignation from all Congress positions and primary membership.