"The workers don't have a long list of demands but nobody is ready to listen to them. They have been suffering since real long... 28 years of strike and still no justice. It is not a short period, " Mahesh told reporters here.
The actor-director also sang a rap song, for which he lent his voice in the film. It is the title track.
Mahesh, who was in the city to promote his film, along with Seema Biswas and Karan Patel, believes he is blessed to be a film-maker in this era.
"I'm blessed I am a film-maker now... as times have changed and the audience has become more sensible and doesn't want to watch trash, which is what inspires me the most to make realistic subject-oriented films, " he added.
"City of Gold" releases Friday in Hindi and Marathi and is based on the plight of Mumbai mill workers after they lost their livelihood in the 1980s. It is also an account of the birth of Mumbai's crime underbelly.
The film features Satish Kaushik, Sachin Khedekar, Seema Biswas and Anusha Dandekar.