Blair may be about to convert, but will that make him a Catholic?

Fraser Nelson says there is anger in the pews over the former prime minister's upcoming conversion. He led, say his critics, an anti-Catholic government, and many believe he should apologise for his support for abortion and stem-cell research before he is received Cy First Confession' would be a great title for Tony Blair's memoirs. At any rate, though the book may be years away, Tony Blair will soon confess his sins to Cardinal Cormac Murphy-O'Connor, and later (no one is sure, but the Vatican has heard it will be after Christmas) Mr Blair will be received into the Roman Catholic Church. And in true Blair style, his decision to 'Pope' is creating a political storm.

In the robustly secular world of Westminster, few care what Mr Blair does with his Sundays. But Mr Blair's conversion is a hot and divisive topic among priests and ordinary Christians in this country — and even in the Vatican itself. Churchgoers who wrote to their MPs in protest against the former prime minister's various policy initiatives, from embryo research to laws on homosexual adoption, have good reason to be puzzled. Has Blair recanted? If he has, shouldn't he say so publicly before he is received? Or has he decided not so much that he will go to Rome, but that Rome will come to him?

Many are remarkably keen to speak on the subject — but few on the record. 'I cannot be identified,' says one senior Vatican source. 'The amount of good I am able to do here depends on it.' There are pressing issues here, however. Some fear that Blair's conversion has no deep theological basis, and that the rules are being bent in a most spectacular fashion to accommodate him Others fear that Blair is no more than a secular liberal with broadly Christian — but not obviously Catholic — beliefs.

If Mr Blair were not a public figure, none of this would matter much; at any rate there would be none of the sort of anger that is now sweeping the pews. It is Mr Blair's prominence and his outspoken religiosity that cause the problem. The former prime minister has spoken with obvious feeling about what he believes and how he fuses his politics with his creed. Alastair Campbell was not comfortable with this, declaring four years ago that 'we don't do God'. But Mr Blair most emphatically does.

Although Anglican, Mr Blair has always attended Mass with his wife, a convent-educated Catholic. He has done so, he says, to keep the family together on Sunday. He has described himself as an 'ecumenical Christian', which appears to mean that he confers on himself the right to attend any service he chooses. In 1996 the late Cardinal Hume wrote asking him to stop taking communion at St Joan of Arc, a Catholic church in Islington. He reluctantly agreed, but wrote in reply, 'I wonder what Jesus would have made of it.'

He might also have wondered what the Anglican and Catholic martyrs would have made of it. Much as it may baffle Blair, people once died rather than deny — or affirm — Catholic Eucharistic teaching; and few practising Anglicans and Catholics would today dream of gatecrashing each other's communion queues. Yet Mr Blair had come to his own, very unique conclusions about religion, and felt confident enough to lecture a Cardinal on Eucharistic protocol.

In Downing Street, Mr Blair's faith was seen as a driving factor in his life — but few saw his beliefs as Catholic. 'If you look at not just his voting record, but his legislative record, he has fought the Church for years,' says one senior official who worked for him at No. 10. 'That is why I cannot see how he can enter the Church now. Converts cannot cherry-pick which parts of the faith they agree with. It's easier for cradle Catholics to dissent, but converts have to sign up to the whole agenda. Perhaps he has changed his mind. I just don't know.'

To critics within the Church, Mr Blair was — as one priest puts it — 'the most antiCatholic Prime Minister of modern times'. Others, especially Evangelicals, go further and describe his policies as broadly antiChristian. He has legalised homosexual civil unions and gay adoptions. He has championed stem-cell research — and with a fervour that contrasts starkly with his friend George Bush's opposition to such research. He voted against lowering the abortion limit from 26 weeks to the present 24. His credentials are those of the perfect secular liberal. All this makes it baffling that he should now choose to join the Church that has so often attacked New Labour's legislative programme. His friend Cardinal Cormac Murphy-O'Connor has been an outspoken critic, but Mr Blair has, apparently, been unmoved.

Joining the Catholic Church is not for the doctrinally fainthearted. The convert must first make confession of his serious sins. Next comes the Rite of Reception which includes the declaration: 'I believe and profess all that the Holy Catholic Church believes, teaches and proclaims to be revealed by God.' Ann Widdecombe says she had struggled with this sentence before being able to convert herself. 'So either Tony Blair will perjure himself on a massive scale, or he has genuinely repented. But we can't send a message that we accept people just because they used to be the prime minister' Other Catholics go further. 'St Paul's conversion on the road to Damascus would pale into insignificance by comparison,' says John Smeaton, director of the Society for the Protection of Unborn Children, who has a dossier on Mr Blair's voting record. 'We need to hear a full repudiation from him Without one, having Blair as a Catholic is like having a vegetarian in a meat-eating club. It simply does not make sense.'

But might there be more leeway in the conversion process than Mr Blair's critics suggest? Some would say that there is. The so-called Tablet Catholics — named after the distinguished liberal Catholic weekly — would argue the case for plurality. Cherie Blair puts it like this: 'The Church isn't just about the Vatican. It's about all of us.' This is the Catholicism of Hans Kung, a Swiss theologian who professes loyalty to Rome but rejects its teaching on celibacy and women priests. That he has been a house guest at 10 Downing Street provides another clue to the Blairs' thinking.

Mrs Blair made her position explicit in an article two years ago in which she confessed to having 'doubts' about some of the Church's teachings. 'But I have been taught that you should stay and try to change things. It's like the Labour party in the 1980s. I wasn't happy with the way it was going, so I tried to help change it from within. Luckily, we won that battle.' For all the breathtaking presumptuousness, one cannot fault her ambition. Today: Westminster. Tomorrow: Rome.

But one cannot join the Church as a liberal Catholic. There is only one kind of Catholicism, and its teaching is laid out in the Catechism. No doubt Cardinal MurphyO'Connor will have discussed the Catechism with Mr Blair; certainly his spiritual adviser will have done. 'If Cormac is for Blair coming into the Church, then there is nothing anyone down here can say about it,' says a senior cleric in Rome.

Many priests I spoke to suspect that Mr Blair's charm may have been impossible for the Cardinal to resist. 'The Catholic Church in England has been working-class Irish for yonks and we've only become socially acceptable in the last 30 years,' says one London priest. 'It can be very flattering when you're courted by the establishment. If Mr Blair came knocking on my door, instead of the usual hobgoblins, I'd be flattered. I can understand if Cormac has been.'

Yet it is just not possible to believe that the Cardinal would allow himself to be seduced into allowing an unsuitable candidate to become a Catholic. But why, ask liberal Catholics, hold Mr Blair to a standard of doctrinal orthodoxy that many of today's faithful would fail? Mr Blair's supporters believe opposition to his joining the Church is confined to a handful of Tories and ultraconservative clerics.

'Those objecting to Tony's conversion are modern-day Pharisees,' says one former aide.

'How many Catholics can genuinely say they agree with every single one of the Church's teachings? Let him who is without sin cast the first stone.' Stephen Pound, a Catholic Labour MP, takes a similar view. 'Perhaps Tony isn't perfect. But there has only ever been one person on this earth who was. If he wants to join the one, true and indivisible Church then we should celebrate the fact.'

In the Vatican Mr Blair's conversion has been expected for some time. When he met the Pope last June he brought as a present a picture of Cardinal Newman, the most famous Anglican convert. The meeting consisted of pleasantries, as is the custom on these occasions. An altogether tougher encounter had occurred earlier when Mr Blair met Cardinal Bertone, the papal secretary of state, who laid out the Church's objections to Mr Blair's legislation. But there is no Papal blackball on his conversion.

There is concern in Rome, however, over the liberal direction of the Catholic Church in this country. According to a senior Vatican source: 'The situation in England, from mass attendance to vocations, is as bad as anywhere.' But things in the US and Germany are bad too. That is why the Pope has decided that there are three appointments that will define what is expected to be a relatively short papacy: new cardinals in New York, Munich and Westminster. All three incumbents have reached the mandatory retirement age.

But finding a successor can be a slow process even under fast-moving Popes. 'The Holy Father is a gentle man, he works very slowly, to the frustration of some,' Jam told. Vincent Nichols, Archbishop of Birmingham, has long been the frontrunner for Westminster. 'But he is the Gordon Brown of the Church,' says once source close to the Cardinal. 'He thought the job should have been his last time, and he's been gunning for it ever since.' The Vatican suspects the Cardinal's preferred choice is Arthur Roche, Bishop of Leeds.

Both may be in for a disappointment. I am told the Pope is sceptical about choosing anyone from England's 'magic circle' of metropolitan bishops and is actively considering monastic candidates to succeed Cardinal MurphyO'Connor — just as Basil Hume was plucked from the monastic seclusion of Ampleforth Abbey in 1976. Those already in Church hierarchy, it is feared, are liberals.

But the Cardinal himself is certainly no patsy. Catholic MPs were this week surprised to receive an invitation to a private soirée to discuss the coming 'parliamentary agenda' — the first time a 'Catholic whip' has been attempted. The head of the Catholic Church in England and Wales is clearly not going to stop his campaign against the anti-Christian policies of this government, or of any other. Tony Blair's conversion may be popular at Westminster Cathedral — but his secular liberalism will not find any sympathisers there. When it comes to his first confession, he will have to follow his conscience — and listen carefully to the advice of his confessor.