The 24-year-old star will soon release her new album Back To Scratch and said she always likes to sing live.
She said to UK newspaper Daily Express: 'I like singing live, I do that in all my performances. I think it's really bad form when artists mime.
'I know some say they can't sing because they are dancing but if I was dancing and it affected my vocals I just wouldn't do it.'
Her comments come just days after Cheryl Cole was criticised for pre-recording her performance of new single, Promise This, on The X Factor.