Legendary comedienne Lucille Ball's daughter has assured actress Debra Messing that no biopic about her mum will ever be made unless she's onboard to play the I Love Lucy icon.

The former Will & Grace star is a huge fan of Ball's and was blown away when her idol's daughter tracked her down at a party recently and told her she wouldn't want anyone else to play her mum.

Messing says, "She came up to me and said, 'I've always said that if they ever did a movie about my mother's life that you would be the person that I would want to play the part', and I started to cry. It was a pretty profound and wonderful moment for me. It was a very generous thing to say."

However, the actress feels sure the Lucille movie will never happen anyway, adding, "No one should touch that."