The wheels are coming off the Tony Blair Faith Foundation following his demands for wholesale changes in Catholic belief and practice. He, his wife Cherie and the foundation were firmly rebuffed in Rome this month at a meeting of the Pontifical Academy for Social Sciences where he was compared to Cromwell and his good faith was impugned.

As architect, with George Bush Junior, of the invasion of Iraq and the consequent death of more than a million Iraqis, the man unwilling to condemn the Israelis' invasion of Lebanon in 2006 and the destruction wreaked in Gaza this year, he has lost credibility among Arabs. He is under attack for failure to achieve progress on Middle Eastern peace as representative of the UN, the EU, the US and Russia. "He is – at best – a total irrelevancy", says Jerusalem-born Dr Ghada Karmi of Exeter University.

Now his newly created foundation has confirmed it is losing its director of policy. William Chapman, a 57-year-old Anglican who worked in Number 10 on appointments in the Church of England, is leaving to become secretary to Ian Luder, the Lord Mayor of London.

The Tablet, a Catholic weekly, quoted Stephen Pound, Labour MP for Ealing North and himself a Catholic, correctly forecasting Blair's hubristic attitude would damage him among Catholics, Muslim and Jews. "It is extremely counterproductive. Entrance to the Vatican is only gained through a series of iron-clad, hermetically sealed, heavily padlocked and bolted doors, and I can hear them creaking shut as we speak." Pound warned Blair against "dictating to the pope through the media".

Much worse news came this month from the Vatican where the couple came under sustained fire at the Pontifical Academy of Social Sciences, a group of scholars which includes the economist and Nobel Prize winner Joseph Stiglitz and Hans Tietmeyer, former head of the German central bank. The meeting (pdf), convened by the pope, was organised by Roland Minnerath, once Vatican diplomat, now archbishop of Dijon.

The attack was spearheaded by Professor Michel Schooyans of the Catholic University of Louvain, a specialist in anthropology and political philosophy. Speaking uncompromisingly, Schooyans accused Blair and his wife of supporting a messianic US plan for world domination.

One of the aims of the Tony Blair Faith Foundation will be that of remaking the major religions, just as his colleague Barack Obama will remake global society. With this purpose, the foundation in question will try to expand the 'new rights', using the world religions for this end and adapting these for their new duties. The religions will have to be reduced to the same common denominator, which means stripping them of their identity ... This project threatens to set us back to an age in which political power was ascribed the mission of promoting a religious confession, or of changing it. In the case of the Tony Blair Faith Foundation, this is also a matter of promoting one and only one religious confession, which a universal, global political power would impose on the entire world.

The Belgian all but ridiculed the former prime minister. "The fresh 'convert' does not hesitate to explain to the pope not only what he must do, but also what he must believe! Is he a Catholic? ... So now we are back in the time of Hobbes, if not of Cromwell: it's civil power that defines what one must believe."

Given the hostility expressed towards Blair in Rome he will be lucky to recruit the outgoing archbishop of Westminster, Cardinal Cormac Murphy O'Connor, to the foundation as he promised. The hostility – and ridicule – that the Blairs and their associates stir up mean he is increasingly unlikely to achieve his ambition of becoming president of the EU.