Lily James says criticism about her waist being made to appear too thin in Cinderella is ‘irrelevant’.

The Disney remake has faced a backlash from US parents who claim the princess has an unnaturally small waist. The Downton Abbey actress, 25, reportedly had to go on a liquid diet to fit into the tight-fitting corset for the role.

‘Why on earth are we focusing on something so irrelevant?’ she asked reporters at the UK premiere. ‘I’ve had friends’ kids and a little boy Daniel who is nine and he said, ‘It’s amazing how you promised your mum to be kind and good and remembered it’.

The live action adaptation has been criticised ever since a trailer showed 25-year-old Lily James in a blue princess ball gown with a tiny waist. Some people accused filmmakers of digitally resizing it to make it look smaller, but the stars denied that at the premiere. ‘The film is about courage, kindness, strength and beauty from within so they’re focussing on the wrong thing,’ James told Newsbeat. ‘I had Sandy Powell create it. The first time I put it on it took my breath away. ‘It’s so beautiful and to wear it, I felt empowered. It felt like it was a suit of armour. I felt unbelievable.’