'There will always be room for newspapers' says Robert Harris

To any journalist struggling to pay the mortgage, fearful for the future of the trade, there are two words of comfort – Robert Harris. The author of novels such as Enigma and Pompeii began life as one before deciding he could make it as a novelist, with extraordinary results. His first four books – Fatherland, Enigma, Archangel and Pompeii - went straight to number one in the bestseller list.

Not surprisingly, success of that kind has brought fabulous wealth. In fact, it has become traditional for journalists interviewing Harris to get their envy off their chests early on in their piece. But talking to Harris about the trajectory that has brought him to this point, it becomes clear that writing was his motive all along. "I've wanted to be a writer since the age of nine, and the only way it was feasible was to go into journalism," he says. Harris's father was a printer in Nottingham, so words had always played a part in his life. "What I really wanted to do was write plays. I wrote them as a teenager and in many ways I'm really a frustrated playwright."

At his comprehensive in Melton Mowbray, he edited the school magazine, and at Cambridge he joined the student newspaper, Varsity, rising to become the editor. As a young man in a hurry, he then went into the BBC, as it was the only way to get an NUJ card without having to do a tour of the regional press. "Perhaps that was a mistake," he says now. "I was too young to be a reporter because I realised that life was just going to be more of this." So when Anthony Howard, then deputy editor of The Observer, asked if Harris would like to cover politics with them, he seized the chance.

His stint in television wasn't wasted: he says it was writing documentaries for the BBC's Panorama that taught him the art of story-telling. But working under Anthony Howard and Alan Watkins, now a columnist on this newspaper, was one of the highlights of his journalistic career. "I loved writing for those two. They had such love of prose. They judged you as a writer. I learnt a huge amount from them."

Although he is glad not to be a journalist any longer, Harris remains a firm believer in the importance of newspapers. He reads several a day and it was an article about Pompeii that inspired him to write his book of that name. The role of the journalist remains vital, he says. "On the whole, I'm optimistic about the future because I think people will always want to read the filtered views of professional journalists. I don't think that's just comforting ourselves, it's just a fact. There is good stuff that's free on blogs and so on, but you have to wade through an awful lot of rubbish to get to it."

But should we pay to read content online? "Yes, I welcome that, but I think the future is probably in packages, whereby you choose which titles you want to read and pay a certain amount a year to get access to them." It's an idea News International and other media organisations are investigating, commonly known as bundling. "Ideally you could have publications owned by different proprietors in your package."

He is less positive when it comes to the BBC, where he loved working, arguing that the licence fee has now become, in effect, a poll tax. "It falls heavily on the poorest in society and I find that hard to justify."

He also questions the diversification of the corporation in recent years, and the stranglehold over the web. "It seems to me completely ridiculous that people with little money should be subsidising people all over the world reading the BBC for free. It's madness. I can't see how it can be sustained." His solution is to create a tiered payment structure, so people pay a licence fee proportionate to their incomes.

There was a time when Harris even toyed with the idea of investing in journalism, when he made a bid for New Statesman magazine in 2001. But the then proprietor, Geoffrey Robinson, rejected his offers and Harris has not returned to the idea since. The following year he gave up his column on The Daily Telegraph to concentrate on book-writing full-time, a pivotal moment in his career. "It was a wet Monday morning, and the book [Pompeii] was in pieces, hopeless, and everything was going badly. But I realised then that I would sooner be writing a novel where everything was going wrong than writing a column where everything was going well."

There is still a lot of the journalist in Harris – he says he could knock out a thousand words in just over an hour if someone rang him up and asked him – but if he has a choice, those thousand words will always be fiction rather than fact, or rather, journalism.

Robert Harris's new book, Lustrum, is published by Hutchinson; £18.99