Pope Francis has reaffirmed the "primacy" of using conscience...
Dozens of conservative Catholic figures have written to the pope, accusing him of promoting false teaching in areas of doctrine including marriage.
Sent to Francis last month, the contents of the document - signed by 65 theologians, priests and academics - have now been made public.
It said: "With profound grief... we are compelled to address a correction to Your Holiness on account of the propagation of heresies effected by the apostolic exhortation Amoris laetitia and by other words, deeds and omissions of Your Holiness."
The statement referred to a Latin-titled declaration ('Joy of Love' in English) made by Pope Francis last year which prompted concerns he was opening the door to divorced and civilly remarried Catholics receiving Communion.
Under current Catholic doctrine, many divorced devotees around the world cannot go up to receive the sacramental bread and wine.
Among the signatories are Dr Joseph Shaw, a research fellow in philosophy at the University of Oxford, and former president of the Vatican bank, Monsignor Antonio Livi.
Speaking with Premier, Dr Shaw said: "It [the letter] represents an escalation, if you like, because it makes more explicit than before that what the pope seems quite clearly to be encouraging is incompatible with faith.
"It [the letter] sends the message that this is not acceptable to an increasingly large proportion of the Catholic faithful, and even if the pope chooses to ignore that it's something that's going to be taken into account by Curia officials."
Said to be the first time a pontiff has received a "filial correction" since the 14th century, the 25-page document accused Pope Francis of taking seven heretical positions.
Pope Francis' Joy of Love letter in April 2016 previously prompted four cardinals to request answers to their questions on the text.
The Vatican is yet to respond to the document.
Click here to listen to Premier's Alex Williams speaking with Dr Joseph Shaw: