Cate Blanchett once had an actress be ''cruel'' to her.

The 'Cinderella' star insists she has only ever had one bad experience with a co-star and attributes the unnamed woman's behaviour towards her to unhappiness.

She said: ''I've only had one bad experience with an actress, quite early on.

''Sometimes when people are unhappy they do cruel things.''

Cate - who has sons Dashiell, 13, Roman, 10, and Ignatius, six, and adopted baby daughter Edith with husband Andrew Upton - admits 'Cinderella' bosses were worried about her character, the vain, calculating stepmother to the title character, appealing to audiences but the Australian actress doesn't care about ''likeability''.

She said: ''I think everyone was a bit concerned the stepmother should be sort of likeable. I'm never interested in likability.

''With every ounce of goodness and kindness that Cinderella throws at the stepmother, she sees how world-wearied and selfish and vain she is. The stepmother feels judged by her goodness.''

Cate's portrayal of the character pays tribute to the Hollywood glamour of 1930s stars like Joan Crawford.

She told Britain's Grazia magazine: ''It was a time in cinema where women's danger was celebrated.''