Former Delhi minister and senior Congress leader Rajkumar Chauhan quit the party to join the BJP on Saturday, a day before the national capital votes in the parliamentary election.
Chauhan was upset with the Congress after he was denied ticket from the North West Delhi Lok Sabha seat. Delhi Congress working president Rajesh Lilothia has been fielded by the party from the seat.
"There was resentment among people over the way I was denied ticket from North West Delhi," Chauhan said.
The former four-time MLA from Mangolpur Assembly segment and minister in the Sheila Dikshit government joined the BJP in the presence of its Delhi unit chief Manoj Tiwari and Union minister Vijay Goel.
Tiwari said the decision of Chauhan to quit the Congress "exposed" the party's policy.
Chauhan alleged his name was in the list of candidates finalised by the Congress's election board but it was removed by an official of party president Rahul Gandhi.
He was MLA from Mangolpur for four consecutive terms from 1993. He was defeated by AAP's Rakhi Birla in Assembly elections of 2013 and 2015.
BJP sources said Chauhan may play a crucial role in the Lok Sabha polls by bringing votes of his supporters to the party.
Chauhan alleged Congress lacked leadership and questioned role of Dikshit as party's Delhi unit president citing her "memory loss" due to old age.
Delhi Congress spokesperson Jitender Kochar said Chauhan was an important leader in the party and it's "unfortunate" that he joined the BJP.
"No leader is bigger than his party. Many others, who like Chauhan quit Congress, have come back. A Congressman can not survive BJP's ideology," he said.
Chauhan said he believed in the policies of Prime Minister Narendra Modi and would work to strengthen bonds of his Khatik community with the BJP.