Sarita Arya had won from Nainital in 2012 but had lost the seat in 2017.
In a shot in the arm for the BJP ahead of the Uttarakhand Assembly polls, the state's women Congress president and former Nainital MLA Sarita Arya on Monday joined the ruling party and has been expelled from the Congress.
The former MLA joined the BJP at its state headquarters in Dehradun on Balbir Road in the presence of Chief Minister Pushkar Singh Dhami, state party president Madan Kaushik and other leaders.
She was expelled from Congress for six years.
Welcoming Ms Arya into the party fold, Mr Dhami said she had always fought for the poor, deprived sections and women. Her entry would definitely strengthen the party, he said.
Ms Arya said she joined the BJP because of a "sense of guilt" as she was not being able to secure tickets for women candidates in Uttarakhand despite being the state's Mahila Congress president.
"The Congress had given 50 per cent of tickets to women in Uttar Pradesh in its first list in accordance with Priyanka Gandhi's announcement. But in Uttarakhand, despite being Pradesh Mahila Congress president, I was not being able to get tickets for them. I was being taunted by women aspirants with remarks that how I could get tickets for them when my own candidature was in doubt," she said.
Ms Arya was keen on contesting from Nainital but was doubtful about the Congress fielding her.
Ms Arya had won from Nainital in 2012 but had lost the seat in the 2017 Assembly polls to BJP candidate Sanjeev Arya, who is now in the Congress.
Sanjeev along with his father and prominent Dalit leader Yashpal Arya had joined the Congress last year and it is almost certain that the party will field him from Nainital.
She had hinted at the possibility of her joining the BJP on Saturday when replying to a question from journalists, she said why wouldn't she join the BJP if it gives her a ticket.
Meanwhile, state Congress president Ganesh Godiyal expelled her from the primary membership of the party for six years, saying her statement to the media in the context of the elections was not in keeping with her position as the Pradesh Mahila Congress president.
It tarnished the party's image, he said in the letter.
Mr Godiyal said the party's state and central leadership had taken it seriously and therefore she has been expelled from the primary membership of the party for six years as a disciplinary action.