Lord Carey, the former Archbishop of Canterbury, has accused David Cameron of "aiding and abetting" a public backlash against Christians, saying the prime minister has done more than any other political leader to "feed anxieties" that Christians are a "persecuted minority" in Britain.
Carey, who held the Archbishopric between 1991 and 2002, also claimed that "an aggressive secularist and relativist approach towards an institution that has glued society" is behind the coalition government's plans to "change the nature of marriage" through in introduction of gay marriage.
The former Archbishop also suggested that recent human rights cases over Christians wearing symbols in the workplace, as well as plans to convert a 700-year old parliamentary chapel into a multi-faith prayer space were also causes of concern for many Christians.
Writing the in Daily Mail on Saturday, Carey said that almost two-in-three Christians in the UK believe themselves to be part of a "persecuted minority", despite Cameron's call for Christian leaders to "stand up and oppose aggressive secularisation".
"Their fears may be exaggerated because few in the UK are actually persecuted," Carey wrote, "but the Prime Minister has done more than any other recent political leader to feed these anxieties".
The 77-year-old said that should legislation for gay marriage be passed, Cameron risks alienating huge numbers of Christians, who previously would have been considered "pillars of society".
However, Conservative former justice minister Nick Herbert hit back over Carey's comments, particularly gay marriage - accusing Lord Carey of "trying to dictate the choices of others".
"How can it be an 'aggressive secularist' agenda to allow religious groups like the Quakers to conduct gay marriages when they want to?" the MP, who is gay, wrote on Twitter.
"The Bill protects religious groups who don't want to conduct gay marriages - why should they have the power to stop others who do?
"So what, Lord Carey, do we call the agenda of religious leaders who are trying to dictate the choices of others outside their faith?"
Andrew Copson, chief executive of the British Humanist Association, said: "Lord Carey's hyperbolic interventions on this issue are becoming as ludicrous as they are predictable.
"His increasingly desperate attempt to work up a victim narrative where Christians are marginalised and persecuted has no basis in reality.
"Time and again the vast majority of the claims of discrimination against Christians that have been tested in the courts have been assessed by impartial judges and found baseless.
"Discrimination against non-Christians is in fact far more widespread than discrimination against Christians, and Christianity is still overly privileged in the UK.
"In almost one third of our state schools, preference is given to Christian parents in admissions over non-Christians, and to Christian staff over non-Christian staff."
The Society's director, Keith Porteous Wood, said in a statement that: "Christians are far from being "marginalised" in this country. The UK is the only country in the world to give bishops the right to sit in its parliament, and England and Wales are the only countries where a daily act of Christian worship is a legal requirement in every state school. These unjustifiable privileges remain despite precipitously declining support, as shown by church congregations declining and ageing for many decades, which continued under Lord Carey's own poor leadership.
"Historically, gay people's lives have been blighted, and indeed ended, by the Church. Dr Carey is determined to continue persecuting them. Mr Cameron should be praised for helping to bring this persecution to an end.
"The UK is a diverse country, and a secular political system is the best chance we have to create a society in which people of all faiths and none can live together fairly and peacefully. There is nothing "aggressive" about this approach. Those practicing religion should show tolerance and more understanding of secularism and recognise the benefits that go with living in a secular society."
Carey's claims come days after the Church of England was accused of 'spinning' a survey on prayer.
The CofE was criticised by the British Humanist Association and Professor Richard Dawkins, among others, for a "misleading" question used to imply more Britons believed in the power of prayer than could actually be shown.
The BHA claimed the survey, conducted by ICM for the CofE, never asked respondents whether they "believe in the power of prayer" but instead asked people what they would pray for, regardless of whether they believe prayer could change anything.
The Church of England said 81% of respondents named specific things that they would choose to pray for, such as world peace, relationship problems or problems at work if they were to believe in the power of prayer.
The BHA said the results of the survey did not prove that four out of five people believe in the power of prayer, or that God would help them through their troubles.