Deora had won the seat for the second time in 2009, in a three-cornered fight with MNS leader Bala Nandgaonkar and Shiv Sena leader Mohan Rawle.
This time around, his fight will be with Nandgaonkar, Shiv Sena's Arvind Sawant and AAP's Meera Sanyal.
The 37-year-old MP initiated the Bhendi Bazar cluster development project, pushed for the Eastern Freeway project and the second phase of the Rs 80-crore Marine Drive makeover project.
He also claims credit for the lighthouse tourism policy, guidelines to regulate cell tower radiations and the state's decision to set up a housing regulator.
Banker Meera Sanyal, who fought the last elections as an Independent, is contesting again, this time as an Aam Aadmi Party candidate. She says her experience as a banker will come in handy if she gets a chance to represent the constituency in Lok Sabha.
The recent Arvind Kejriwal road show in south Mumbai has energised Sanyal's campaign. The AAP chief had kicked off his Lok Sabha campaign in Maharashtra with a ride on a suburban train to Churchgate and then took out a 'Jhaadu Chalao Yatra' through south Mumbai streets.
MNS leader Nandgaonkar, who finished second against Deora last time, will be vying for the "Marathi manus" votes and dampening the chances of the Sena candidate and former legislator Arvind Sawant.
Nandgaonkar, who was minister of state for home in 1995-1999, had hogged the limelight after defeating Chhagan Bhujbal in the 1995 assembly polls.
South Mumbai is a high-profile constituency which has its own share of development issues like inadequate water supply, parking problems, illegal hawkers, contaminated water supply due to intermingling of water and drainage lines and re-development of old and dilapidated buildings.
In the 2009 Lok Sabha polls, Deora was believed to have benefited from the vertical split in Shiv Sena votes due to the entry of Nandgaonkar. He had polled 2.72 lakh votes against 1.59 lakh votes polled by Nandgaonkar and 1.46 lakh by the Sena's Mohan Rawale, while Sanyal secured 10,157 votes.
Rawale was expelled from the Sena last year.
The Mumbai South constituency comprises six Assembly segments -- Worli represented by Nationalist Congress Party's Sachin Ahir, Malabar Hill by Bharatiya Janata Party’s Mangal Prabhat Lodha, Sewree by Nandgaonkar, Mumbadevi by Congress' Amin Patel, Byculla by Congress' Madhu Chavan and Colaba by Congress' Annie Shekhar.
Sawant, who was member of the legislative council for two terms, said the state government has "failed" to address two key issues, namely redevelopment of dilapidated buildings, slums and port areas.
"I feel the state government is responsible for the plight of the textile workers as due to ill-advised policies, all textile mills in the city were closed and lakhs of workers were rendered jobless," he said.
Image: Congress leader Milind Deora
Farhan Azmi may take on Milind Deora in Lok Sabha polls
'I used to play the guitar but I now I only play the fool'
'People can see cracks in the Sena ideology'
'Spoiler' Sanyal bats for Mumbai
A transcript of Meera Sanyal's chat on rediff