Parker was approached to play feminist Gloria Steinem in the forthcoming biopic following Moore's decision to check into rehab after suffering a seizure on January 27, reported

Showbiz spy.

But Parker, 46, believes she might not have had the courage to join the movie which is based on the life of porn actress Linda Lovelace had she had more time to think.

"They explained the circumstances and asked if I would read the script quickly that there was a sense of urgency and I didn't know at the time they were down to their last few days of shooting on the whole movie.

"So I read the script and I didn't have the right amount of time to think about it properly. Had I, I probably would have said no because it was a daunting experience for lots of obvious and less obvious reasons," Parker said.

The mother-of-three hopes she has managed to do justice

to the role in Moore's absence.