The Congress sprang a surprise on Friday when Rama Pilot, a member of Parliament and widow of Rajesh Pilot, filed her nomination from Rajasthan's Jhalrapatan constituency.
The Bharatiya Janata Party's chief ministerial candidate, Vasundhara Raje, is contesting from here.
Pilot, who represents Dausa constituency in the Lok Sabha, submitted her papers in the presence of party workers, District Collector Praveen Gupta said.
The Congress had earlier announced Mohanlal's name for the constituency.
BJP leaders, including Pramod Mahajan, went into a huddle soon after Pilot filed her nomination, party sources said.
Meanwhile, Raje said she would contest only from Jhalrapatan.
"I am taking on the challenge," BJP sources quoted Raje as having said, a day after the party announced she would also contest from Pilawa seat.