Former Uttarakhand chief minister Narayan Dutt Tiwari and his son Rohit Shekhar Tiwari – both Congress leaders – joined the Bharatiya Janata Party on Wednesday. The Tiwaris were inducted into the saffron party in the presence of BJP chief Amit Shah in Delhi. They are believed to have agreed to the crossover after Rohit Shekhar Tiwari was promised a ticket from the state’s Kumaon constituency, according to The Indian Express.

“Have you seen respect being given to my father by Congress?” Rohit Shekhar Tiwari told ANI after news of their new allegiance broke. “He’s totally forgotten [by the party].”

However, ND Tiwari’s nephew Manishi Tiwari alleged that the senior leader was not in the right state of mind to make such a decision. “I think this has been done on the behest of a few who have vested interests. They want to seek political mileage out of it,” he told ANI. “He is not mentally well. I am sure ND Tiwari does not even know that he has joined the BJP.”

The move comes as a major setback for the Congress ahead of the Assembly elections in Uttarakhand on February 15. ND Tiwari had served as the Uttarakhand chief minister from 2002 to 2007. The 91-year-old party veteran had also been the Uttar Pradesh chief minister three times between 1976 and 1989 and had held the governor’s post in Andhra Pradesh from August 2007 to December 2009.

The party veteran was dragged into a controversy in 2013 after his son filed a paternity suit against him. Initially, ND Tiwari had refused to undergo a DNA test. The Delhi High Court had declared Rohit Shekhar Tiwari his biological son after tests confirmed it in 2014.

ND Tiwari’s induction into the BJP may help the party consolidate votes from the Brahmin community, reported India Today. BJP spokesperson Munna Singh Chauhan told PTI that the senior politician, who enjoys immense popularity in Uttarakhand and Uttar Pradesh, will strengthen the party’s chances in the election.

The 91-year-old is not the first prominent Congress leader to join BJP in Uttarakhand. Earlier, 11 Congress MLAs, including former chief minister Vijay Bahuguna and Harak Singh Rawat, had quit the party to join the BJP.