Edinburgh Fringe satirists aim their fire at Christian right

We have nothing to fear from al-Qa'ida. Christian fundamentalists are the real extremist threat. That's the message from the writers of a new play being shown at the Edinburgh International Fringe Festival.

Cash in Christ, a sing-along play satirising the modern capitalist "mega- church", is arguably one of the most controversial productions in a Fringe with the largest satirical content in living memory.

Other offerings this year include Jihad: The Musical, Tony Blair – The Musical, and others centred on the porn film Debbie Does Dallas, orgasms, Asbos and thoughts of BNP members.

Cash in Christ is so controversial it had to be passed by three lawyers before it could be performed at a festival in Australia.

The 50-minute show, written by Van Badham and Jonny Berliner, which premieres this weekend, comprises sermons from Christian literature, television programmes and church services. The authors conducted extensive research in America, Australia and online, and also spent three months attending services at London churches, including the Hillsong Church and Holy Trinity Brompton.

The show – pitched as "putting the fun into fundamentalism" – features fundraising evangelical preacher Fanny Comfort and her husband Bob singing songs such as "Christian Rock (Is Cool)" with lines about "guitars exploding like a bomb".

The writers said that, while there is public discussion about the dangers of radical Islamic groups, the influence of the Christian far right is underestimated. "I've been very sensitive to extremists in other religions, particularly Islam, being demonised," said Badham. "I find the Christian right groups that are enormously powerful in our own culture a larger numerical threat than extreme Islam. They are somehow removed from public criticism, and that is one of the reasons we did the show.

"Bush is from the religious right and he has the bomb; that terrifies me far more than the potential of other extremists to get their hands on nuclear weapons. In the religious right it is the self-appointed moral majority that sets its own rules, and anybody opposing them is labelled unpatriotic and shouted down."

Badham said the Wisepart/Jews and Communists co-production is entirely fictitious, but reflects wider political concerns. "It terrifies me that a few religious groups were able to cause a furore around Jerry Springer – The Opera in Britain. What I find frightening about the war in Iraq is that Bush and the people around him speak about it as if it's the crusades again."

She said that although people they met at church services were kind, she felt their attitudes might foster religious intolerance. "The propaganda is intense. We have been going to these megachurches to be told: 'Christianity is not a religion. It is the work of God to rescue all of humanity.' So everybody else can basically get stuffed."

Gary Clarke, pastor at Hillsong Church, London, said he wouldn't apologise, but that he might well laugh. "If you can't laugh at yourself then things have probably become far too serious, and keeping a good sense of humour about things is one of the most important components in having healthy conversations with people from all walks of life," he said.