With less than week to go for elections, Lovely's inclusion into BJP will boost its chances in MCD polls and further weaken the Congress party, which is already on the edge after the debacle in recently held Assembly elections in UP and Uttarakhand.
"Former DPCC President Arvinder Singh Lovely, a former Minister, and former Youth Congress leader Amit Malik joined the Bharatiya Janata Party in the presence of party chief Amit Shah," the Delhi BJP said in a tweet.
"After Arvinder Singh Lovely's joining, I am getting loads of calls from Congress leaders. They feel suffocated in the Congress and want to join the BJP," BJP leader Vijay Goel said on his Twitter account.
Lovely, who is a close aide of former chief minister Sheila Dikshit, had reportedly criticised the working style of Maken.
According to PTI, Lovely said somebody who lost his election deposit, a reference to Maken's heavy loss in the city's assembly polls, was foisted on the party.
He had resigned from his post of DPCC President after Congress' disastrous performance in 2015 Assembly elections but remained in the party.
Lovely was elected to the Delhi Legislative Assembly on a Congress ticket for the first time in 1998, where he was the youngest MLA. He became cabinet minister in the Delhi government headed by Sheila Dikshit and held the portfolios of education, tourism, languages, Gurdwara election and Gurdwara administration.
There was resentment among Delhi Congress leaders, including Lovely, over ticket distribution for polls.
Senior Congress leader Ahmed Patel had reached out to senior leaders of Delhi Congress and promised to look into all aspects of ticket distribution.
Congress has fielded candidates on all the 272 wards in a bid to revive itself in Delhi after facing a rout in 2015 Assembly elections in which it drew a blank.
The opponents of state unit chief Ajay Maken including have reportedly complained to the party high command of 'favouritism and role of money' in ticket distribution.
Voters will exercise their franchise in the Delhi municipal polls on April 23 and results will be declared on April 26.
The Municipal Corporation of Delhi was trifurcated in 2012 into North, South and East Municipal Corporation or NDMC, SDMC and EDMC respectively.
The BJP has been ruling the MCD since 2007. The last polls were held in 2012.