The star - real name Amelia Warner - has recorded a rendition of the band's classic 'Please, Please, Please Let Me Get What I Want', which has been used for the John Lewis Christmas advert.
The singer told The Daily Telegraph that Morrissey has described her interpretation as "delightful", while guitarist Johnny Marr has said that he "thinks it's great".
However, Warner has received criticism from the band's fans online. She explained: "I've had a few people being furious at me on Twitter, saying, 'How dare you?'
"But I haven't done anything to the original. I think you'll find it still exists."
Marr has previously denied fans' claims that allowing John Lewis to use the track for their festive campaign "sullied" the song's legacy.
He wrote on Twitter: "Writing 'Please Please...' one Friday in '84 is one of the best memories of my life. This ad has not sullied that memory one bit."
Slow Moving Millie's version of 'Please, Please, Please Let Me Get What I Want' is available to download now.
> John Lewis Christmas advert meets classic horror - video
Watch the music video for Slow Moving Millie's 'Please, Please, Please Let Me Get What I Want' below: