Seated comfortably in her East Oxford house, author Jan Mark tells me that she sees herself as a speculative writer rather than a science-fiction writer. Her writing is not the stuff of fantasy, but rather an educated guess about where progress will take us. Well-known for her prolific output of children's books, she has recently built up a reputation for adult fiction as well.

"I've done science fiction before, but the hardest one was Eclipse of the Century where I was writing one year ahead, about things that people were going to be around to measure."

In her latest book, Useful Idiots, progress has taken us to a United States of Europe, some centuries in the future, when the ice has receded, the seas risen and the east of England is once more under water. It is a world where the 'Inglish' are 'aboriginals' who live on reserves and demand the right to live as they wish, rather than as the government decrees.

The central idea for the book came initially from a body, dubbed 'Kennewick Man'. "He was a skeleton found in Washington State, on the banks of the Columbia River, a native-American man who turned out to be Caucasian, then turned out to be thousands of years old and pre-dated any native American presence.

"It is also about people wanting their skeletons back - and their shrunken heads. A lot of museum curators now are thinking twice about displaying human remains."

In the novel, archaeology is frowned upon as an academic pursuit and archaeologists are viewed with some disgust by the rest of society. The discovery of a skeleton, unearthed by a vicious hurricane that sweeps across what is left of the islands to the north-west of Europe, causes a chain of events that go to the very heart of all that has been repressed and controlled in order to produce a centralised, 'civilised' society.

She shows me a newspaper article listing museums worldwide with human remains that have been demanded back by their original owners. The issue is obviously a contentious one.

"The trouble is that's what people, on the whole, want to go and look at. There's that sad little dessicated corpse in the British Museum, in sand - where he was found, mummified naturally. There's always a throng standing round him. The lengths the Egyptians went to bury their pharaohs so they would not be found - and here we are digging them up, X-raying them, autopsies. That was the background for the book."

The world of Useful Idiots allows no sickness, ageing or even a blemish. Everything is vaccinated against. But the knowledge that these people are physically 'perfect' only dawns on the reader slowly.

She says: "I notice this 'perfection' with these new, manufactured pop groups. The members are interchangeable, boys and girls - they all have the same features."

But is this the chicken or the egg? Are the kids chosen because they all look alike or are they moulded?

"The trouble is, they can be moulded these days. There are girl's magazines with articles on facial surgery."

She has also chosen what some may already see as an anachronistic art form - the ballet - to imply the difference between the huge, muscular perfect city-dwellers and the smaller, flawed Inglish. In Useful Idiots, the protagonist, Korda, gets involved with an Inglish woman, Freda, a ballet dancer who has various disfigurements related to being human.

Her jaundiced view of academia, reflected in the infighting of the archaeologists in her novel, came from her teaching at Oxford Polytechnic, now Oxford Brookes. "I was writer-in-residence there, so I got a view of the factionalism. Academics make politicians look like pussycats.

"Your entire reputation depends on what you publish and it is all peer-reviewed, so there's always this feeling that you're being got at by a rival. Being writer-in-residence, I was not actually staff, so I could observe."

The job at Brookes is what originally brought Jan Mark to Oxford many years ago. She had previously spent several years teaching in Norfolk, which is how she comes to know the area and describe it so minutely in the novel.

"Where we were - that had all been underwater. So I was only really describing what had been there originally and what will come back. The whole South East is sinking, we are rocking on the edge of the Continental shelf. We've been up and down several times."

Readers of Jan Mark, hold on to your seats and be prepared for a bumpy ride.

Useful Idiots is published by David Fickling at £12.99.