Playing Judy Garland saw Renee Zellweger re-examine her long-held beliefs about her childhood idol and reappraise her own life, she tells Des Sampson.

When Renee Zellweger was first offered the coveted role of Judy Garland in Judy, she whooped with delight at the prospect of portraying her heroine.

But soon after, fears and doubts began to weigh heavily upon her — especially when she discovered that director Rupert Goold was adamant she had to perform all of Garland's showstopper songs herself, live, for the biopic to work.

"I really didn't want to do it, because I've never sung in front