NCP chief Sharad Pawar pitched for a stable government at the Centre and urged citizens to come out in large numbers to cast their votes as he exercised his democratic right on Monday.
Voting was underway for the fourth phase of Lok Sabha polls in 72 parliamentary constituencies spread across nine states.
In Maharashtra, polling was being held in 17 seats, including Mumbai.
"Today is an important day for the country. It is required that a stable government is formed. It is expected that Mumbaikars will not lag behind, and will exercise their voting right by coming out in large numbers and voting decisively," Mr Pawar, the former Union minister, tweeted in Marathi.
Earlier, BJP MP Poonam Mahajan, Congress nominee Urmila Matondkar, industrialist Anil Ambani and actor Rekha cast their votes in Mumbai in the initial hours of polling.
State education minister Vinod Tawde, BJP candidate from Mumhai-North East Manoj Kotak and Congress nominee from Mumbai-Central Eknath Gaikwad were also among the early voters.