Uttarakhand Congress leader Yashpal Arya joined the Bharatiya Janata Party (BJP) in the presence of party president Amit Shah here on Monday.
Arya earlier said that he was upset with Chief Minister Harish Rawat's style of functioning and was feeling ignored in the party.
His son Sanjiv Arya and an ex-MLA Kedar Signh Rawat also joined the BJP today.
The latest political development in Uttarakhand comes just days before the assembly polls.
Commenting on some Congress leaders' joining the BJP ahead of the polls, Chief Minister Harish Rawat has said they might have some compulsion for leaving the party.
Uttarakhand goes to polls on February 15.