Pope Francis is among Catholic Church leaders accused by heads of pro-life organisations from 13 countries around the world of undermining their movement through ambiguous statements and doctrines 'directly contrary to the teaching of Christ'.
In a letter published online, the signatories say that over the past 50 years the pro-life movement has 'relied in a particular way on the immutable teaching of the Catholic Church, which affirms the moral law with the greatest clarity'.
They add that in recent years that teaching has increasingly been replaced by 'ambiguity, and even by doctrines directly contrary to the teaching of Christ and the precepts of the natural law'.
The letter accuses the Pope of statements and actions which 'contradict the Church's teaching on the intrinsic evil of contraceptive acts' and 'contradict the Church's teaching on the nature of marriage and the intrinsic evil of sexual acts outside the union of marriage'.
It also attacks his approval of the UN Sustainable Development Goals which, the letter claims, 'effectively call for member states to achieve universal access to abortion, contraception and sex education by 2030'.
And it condemns the 'approach adopted towards sex education, particularly in chapter 7 of Amoris Laetitia and in The Meeting Point programme produced by the Pontifical Council for the Family'.
Those from the UK who signed the letter are John Smeaton, the chief executive of the Society for the Protection of Unborn Children (SPUC), Greg Clovis of Family Life International UK, and Dr Thomas Ward of the National Association of Catholic Families.
The Irish signatories are Patrick Buckley of European Life Network, John Lacken of Legio Sanctae Familiae and the Lumen Fidei Institute, and Anthony Murphy of Catholic Voice.
Smeaton issued a statement criticising the Pope, saying: 'Over the last couple of years Pope Francis and Vatican authorities have capitulated to the 'culture of death' by supporting the pro-abortion United Nations Sustainable Development Goals and by promoting the agenda of the international sex education lobby through Amoris Laetitia and the Pontifical Council for the Family's pornographic sex education programme. This has a direct effect on real children and real families.'
Smeaton added: 'For this reason the pro-life movement cannot bury its head in the sand and ignore what's happening at the highest levels of the Church today.
'We must ceaselessly demand that our priests and bishops teach the fullness of the Church's doctrine and do not collaborate, even for a moment, in the dissemination of errors that are tragically being spread by His Holiness Pope Francis and by many other senior members of the hierarchy. If we fail to take this stand we will be failing in our duty to the weak and vulnerable children that we have pledged to protect.'
The letter came as Cardinal Walter Kasper of Germany declared that the controversy over Amoris Laetitia is 'hopefully over'.
Following the official publication of the Pope's letter to the Buenos Aires bishops clarifying the matter, the Cardinal said that the admission of divorced and remarried people to the sacraments in certain individual cases is now the only correct interpretation of the document.
In an article for the German language edition of Vatican Radio, translated by the Catholic News Agency, Cardinal Kasper said that 'with the official publication of the letter from Pope Francis to the bishops of the Buenos Aires region, the painful dispute over the apostolic exhortation Amoris laetitia is hopefully over.'
He added that the 'great majority of God's people have already received [Amoris Laetitia] with gratitude and may now feel confirmed'.
He accused the Pope's critics of 'one-sided moral objectivism' that fails to appreciate 'the importance of the personal conscience in the moral act'.