Former Union power minister R.K. Singh resigned from the BJP on Saturday, hours after the party suspended him for anti-party activities.

Singh, the former home secretary turned politician, had touched a raw nerve by accusing a scam in awarding a thermal power project tender in Bhagalpur by the NDA government to a Gautam Adani group company.

Singh, who served as the power minister in the Modi government from 2017 to 2024, had publicly questioned the Bihar government’s decision to award the plant to the Adani group instead of the public sector NTPC.

He had claimed that Union finance minister Nirmala Sitharaman had announced that the power project would be developed by NTPC. Singh had argued that the PSU could have implemented the project at a lower cost than the Adani group. He had also accused the Bihar government of agreeing to purchase electricity from the Adani plant at an inflated rate of ₹6 per unit.

He had alleged a scam amounting to over ₹60,000 crore, stressing the project had been awarded at a much inflated cost.

The Congress had seized on his remarks to mount an attack on the ruling NDA, accusing it of benefiting Adani.

“I have sent my resignation to the party,” Singh posted on X, attaching a copy of the showcause served to him by the Bihar BJP for anti-party activities and his resignation to BJP president J.P. Nadda.

In his resignation letter, Singh said the BJP had not specified the charges against him.

“The showcause is probably because of my statement against the distribution of tickets to people with a criminal background. The statement is not anti-party. It is in the interest of the nation, the society at large and the party to stop criminalisation of politics and to curb corruption,” he wrote. “Some people in the party are not comfortable with this,” he added.

The BJP’s showcause letter stated: “Your activities are against the party. This falls under violation of party discipline. The party has taken this matter seriously, and it has caused harm to the party. Therefore, as per instructions, you are being suspended from the party and asked to explain why you should not be expelled from the party. You are hereby directed to clarify your position within one week of receiving this letter.”

In the run-up to the Bihar Assembly polls, Singh had found common cause with Jan Suraaj founder Prashant Kishor and sought clarifications from some key Bihar BJP leaders facing corruption charges.

A 1975-batch Bihar cadre IAS officer, Singh previously had served as home secretary in the UPA-II government. After retiring in 2013, he joined the BJP and won the Arrah Lok Sabha seat in 2014 and 2019 before losing in 2024.