Sinead O'Connor -- Lied About Pope Duet Plans

American Music Awards sources are saying they never wanted Sinead O'Connor to stand alongside Pope Francis on their show ... they say she was the one pushing for the appearance.

Sources close to the production tell TMZ ... it was actually HER team who contacted the AMAs ... but having Sinead end her Pope beef during the show was NEVER discussed.

We're told show producers were interested in Sinead being on the show ... but they say her claims about the Pope -- which she made on her blog -- are ridiculous and a tweet was never sent.

Sources say producers feel Sinead's been spewing BS for decades, so this rant is nothing new. More importantly ... we're told she will absolutely not be appearing on the award show now.

Sinead famously ripped apart a photo of Pope John Paul II during her 1992 performance on "Saturday Night Live" ... which got her banned from the show for life.