"Soha found the part quite daunting after Sharmila went to rehearse her scenes with Soha. The first scene between them was a difficult and long one. Soha admitted later she was terrified of her mother," the film's director-producer Sangeeta Datta said.
Bringing the real-life mother-daughter duo together for the first time on the silver screen, the English language film about a Bengali diaspora family has 64-year-old veteran actress Sharmila playing mother to Soha.
"I think the real mother-daughter relationship made it very difficult for Soha, because the film deals with the mother's death. She had to explore very dark areas of her psyche for the role," Datta told PTI from London.
However, after a lot of takes and re-takes, 32-year-old Soha, best known for her role in Aamir Khan's 'Rang De Basanti', managed to impress the UK-based director.
"But the scene worked out so well. Soha has given her best performance to date," she said praising the actress's skills.
Sharmila and Soha had earlier rejected many offers to act together in Bollywood, but 'Life Goes On' was chosen as the script brings them together in an organic way.
"I wrote the first draft with Sharmilaji in mind. She is for me the classical mother in Indian films. Sharmila was on board from the beginning because she liked the script and contributed creatively as well," Datta said.
Inspired by Shakespeare's 'King Lear', the film tries to find a new ground for the Elizabethan period drama in a contemporary multicultural British context.
A gripping emotional family drama of generational conflict, the film centres on the experiences of the Indian diaspora in Britain in the context of the prejudice against Muslims due to global terrorism and the Iraq war.
Having already won awards at the Pravasi International Festival at Delhi and the London Asian Film Festival, it was also screened at the prestigious Cannes film festival amid applause.
On why she shot the film in English, the director said she did not want to follow the trend of Bollywood stars pretending to be 'desi' British.
"My aesthetics determined the language of the film. If the characters were all speaking in Hindi, it would ring very false. But my film follows the route of real cinema where people talk and dress as in real life," Dutta said.
Having worked as an associate director in Rituparno Ghosh's films, Datta is now planning to make a film in Bengali.
"I would love to make a film in Bengali. I have a script and plan to move on that soon. The economics of a Bengali film are now well worked out," she said.
Also starring Om Puri and Girish Karnad in important roles, 'Life Goes On' releases on March 25 in India.