"I've been writing it for about 20 years," he reveals. "It's about a teacher who gets special powers and can make impossible things happen. It came from the HG Wells story The Man Who Could Work Miracles. We've got Simon Pegg in the lead and we are just looking at locations. We are shooting it a stone's throw away in Hornsey Lane so that's a relief." The film is also a partial Python project with Cleese, Palin and Gilliam doing voices, alongside Robin Williams who plays Dennis the dog. 

Looking around Jones's study gives one some insight into his life. By the window there is a BAFTA Award given to the Pythons in 2009 for their Special Contribution to Television. Alongside it is a picture of Jones – in a Victorian frock – next to his two older children, Bill and Sally. The shelves groan with comedy books but also books on Chaucer, the history graduate's favourite period. There are also new copies of Erik the Viking, his version of the Icelandic sagas first published thirty years ago. Jones has been having a look at the book again because (at the time of our meeting) he is about to talk about Erik at the British Museum's Vikings Exhibition.

It is an enduring era that is close to Jones' heart: "I wrote Erik because I was disappointed by the original Icelandic fairy tales I was reading to my son Bill. I thought they would be full of magic and dragons and they aren't. They are all about feuds. Somebody goes and steals somebody's cow so the other person kills their cow and then the other person kills their daughter and it all escalates. We did a skit of Njal's Saga in Monty Python called Njorl's Saga, which was all about how Njorl never gets started on his adventures because it's all about explaining how so-and-so married so-and-so and so-and-so married so-and-so, which I must admit is a bit like what they are actually like."

With all of these different strings to his bow it is hard to know where to begin when attempting to describe this consummate polymath. How would he describe himself? "I'm just a lucky blighter, I'm able to do anything I like. I'm just so lucky. Python opened up so many doors." He sips his coffee and ponders on how things could have turned out differently back in the mid-1960s when he left Oxford and was thinking about a career in television.

"I wrote to everyone and was accepted as a copywriter for East Anglia Television. I was just about to go and Frank Muir's office rang and said would I like to come in and have an interview with Frank. He was BBC Head of Comedy. I always wanted to ask Frank why he chose me. He said 'come round, we'll give you two desks, four telephones and two typewriters.' I was there when they cooked up Til Death Us Do Part and The Frost Report which John Cleese and Graham Chapman wrote for." Jones's job also reunited him with fellow Oxford Revue performer Palin and eventually the Python team came together. "I'f I'd gone to East Anglia Television I'd have sunk without trace. I was so lucky."

One thing Jones does not have time for, however, is watching television. There isn't actually one in the house. "We had one but we didn't really use it. It was just sitting in the garage, so I gave it to the dustman last week." As a result he is not very up to speed on modern comedy, "I like Eddie Izzard, he's brilliant. I'm hoping he'll play the headmaster in my film. And Anna and I both like Dylan Moran." He calls his wife up to be reminded of the other comedian he enjoys. "Casey someone? Oh, Louis CK."

There is clearly a more serious side to Jones. After the Iraq war he was very vocal about his opposition to the War on Terror, writing numerous newspaper articles. "I couldn't keep quiet. I was just so furious, a million people dying and Blair was lapdog of the Americans. Somebody tried to carry out a citizen's arrest on him recently in a restaurant and he just talked about Syria and laid into the guy."

So what keeps Jones awake at night, apart from the caffeine? "I've just made a documentary with my son's film company, Bill and Ben, about the 2008 crash. I narrate it. It was funded by a Dutch Risk Management Company. They want to warn people that there is going to be a disaster, the economy is going to collapse again. I think they might be onto something the way house prices are going up. It's just a bubble." 

He manages to balance being serious with his childlike imagination, but resists thinking too hard about his creativity. "I just hope that inspiration comes. I'm having a bit of a block at the moment." This does not stop him continually taking on projects, however. "I'm writing a musical, Nutz, with Jim Steinman based on Tchaikovsky's Nutcracker Suite, set in a children's home. He's written lyrics and I've written the book." Steinman is a regular collaborator with Meatloaf and Jones was originally approached to write a musical of Bat Out Of Hell, "but I couldn't get on with the music so they asked me to do this instead." 

With his love of history I wonder if Jones would have liked to have lived in the past. What about Viking times? "Not at all," he shudders. What about Chaucerian England? "If I'd lived then I'd have been dead by the time I was 27! Life expectancy was fine if you lived a healthy life, but I had a burst appendix when I was 27 and it would have killed me. Maybe the 1960s would be a pretty good time. But you have to be lucky. If I'd gone to East Anglia TV I don't know where I'd be now."

The 02 will no doubt prompt renewed interest in Monty Python. There has already been talk of an American tour. "Everybody else agreed to do the show in America but Mike Palin has scotched the American tour. He says he's too busy…." Are the Pythons quintessentially English? "Well, we are popular in Japan so I don't think so. Humour is pretty universal. We are waiting to break into the Chinese market. I see no reason why not."

The Saga of Erik the Viking by Terry Jones, is published by Pavilion Children’s Books.