They go in two-by-two, as most people imagine the Biblical story of the flood.

But writer of the new 90-minute drama The Ark managed to get his top slot on prime time television by telling the BBC it was not about animals.

Writer Tony Jordan, who had a hit with The Nativity in 2010, starring future "Doctor Who" Peter Capaldi, told the BBC the £2 million show "is not Peppa Pig, it's not about animals, but this is religion that will work in primetime."

Speaking to Radio Times, he says he believes Noah did exist. In the programme, he has Noah say: "Only an idiot would say there is no God."

Jordan, a former market trader who left school at 15 with no qualifications, and has gone on to write a string of hits including EastEnders, Hustle and the time-travelling police drama Life on Mars, also admits: "I struggle to decide what sort of Christian I really am."

The Ark references the present with lines about "the rich getting richer, and the poorer falling further and further into debt" and about "men who defile children".

Jordan says: "You have to believe in and care for Noah and his family so that's what I try to make the audience do in the first few minutes. My story is about making a choice. In Noah's case, about whether to believe in and to obey God. And for his family, whether to obey their father, even though they think he could be off his head. That's the heart of it."

David Threlfall, star of Channel 4's Shameless, and Joanne Whalley, who recently played Katharine of Aragon in Wolf Hall, play Noah and his wife Emmie.

Jordan said he researched biblical accounts of the Flood and also the Koran, where Noah is called Nuh.

If The Ark is a success, Jordan intends to pitch a series of six Biblical stories to the BBC.