Balloting in Uttarakhand for all its five Lok Sabha seats began Wednesday, officials said.
As many as 74 candidates are in the fray.
Harish Rawat had won from Hardwar in 2009 and served as union minister for water resources but resigned earlier this year after being appointed chief minister.
BJP candidate and former chief minister Maj. Gen. (retd) B.C. Khanduri is pitted against Harak Singh Rawat of the Congress in Garhwal.
Saket Bahuguna, son of former chief minister Vijay Bahuguna, will fight for the Congress from Tehri Garhwal constituency against Mala Rajya Laxmi Shah of the BJP.
In 2009, the Congress had bagged all five seats.