Vidya Balan may replace the gorgeous Aishwarya Rai in ‘Pa' that also stars Amitabh Bachchan and Abhishek Bachchan. 'Pa' is to be directed by ad filmmaker R Balakrishnan whose maiden feature film ‘Cheeni Kum' is being appreciated all over.

Although Balki (as Balakrishnan is often referred) had thought of casting Ash in the film earlier, news has come in that Vidya may step in the project instead of the Bachchan daughter-in-law in the role opposite Abhishek.

'Pa' will not only be produced by Sunil Manchanda, who produced 'Cheeni Kum', but also have musical notes from Illayaraja, who is being appreciated for his work in 'Cheeni Kum'.

'Pa' is a very light comedy film portraying the relationship between a father and son.

Balki wrote the movie's script with both Bachchan and Abhishek in mind. And when he narrated the story idea to the father-son duo, they immediately agreed to do the movie.

'Pa' will also have Paresh Rawal in an important role and is ready to go on the floors in due time.