These articles, written by Charles Cumming, were published in The Times and The Sunday Express respectively.

Recently I had the unusual experience of being accused by an eminent British historian of breaking the spirit of the Official Secrets Act. In a review of my novel A Spy By Nature, which appeared in a Sunday newspaper, Andrew Roberts suggested that I had taken a considerable risk in writing about being approached for recruitment by MI6.

"I can attest," wrote Roberts, "that the novel is absolutely accurate in every detail, down to the appearance of the buildings, wording of the correspondence and nature of the cognitive tests. Anyone wishing to join the Secret Intelligence Service (SIS) should buy this book before undergoing the recruitment process."

Was Roberts right to suggest that I had, in effect, broken the law? The short answer is yes. In an ideal world, secret intelligence organisations should remain secret, and those of us who come into contact with them should keep our mouths shut, if only out of loyalty to Queen and country.

In my defence, I would argue that any number of British novelists -including John Buchan, Somerset Maugham and Graham Greene -have used their experiences in the secret world to inform works of fiction.

This does not always go down well with the powers that be. In his recent biography of Sir Dick White, Tom Bower revealed how frustrated the former chief of MI6 was over the publication of The Spy Who Came in from the Cold. "John le Carre hasn't done us any favours," White told the director of the CIA during a dinner in the 1960s. "He makes all intelligence officers look like philanderers and drunks. He's presenting a service without trust or loyalty, where agents are sacrificed and deceived without compunction."

My own encounter with MI6 began in 1995. I was 24 years old and had recently graduated from Edinburgh University with a first in English literature. Not knowing what I wanted to do with my life, I had frittered away several months in London, laying court covers at Wimbledon and working as a waiter in a failing Polish restaurant. However, at a dinner party hosted by my mother in the early spring, I found myself sitting next to a man -let's call him Anthony -who told me that he had "recently retired from the Foreign Office". In short, Anthony and I got along very well. Several days later he buttonholed my mother in the local Sainsbury's.

"I liked Charlie a lot," he said. "Has he thought of joining the Diplomatic Service?" For my mother -whose hopes of her only son becoming a doctor or lawyer had been cruelly dashed many years before -this was a godsend. On the phone that evening I was enthusiastically encouraged to take up Anthony's offer; within a few days an envelope had arrived at my flat in London.

Written on official Foreign and Commonwealth Office paper, the letter invited me to attend an interview at an address in Central London. I was not asked to prepare any subjects for discussion, only to fill out a short application form and to submit the names of three referees for the purposes of vetting. The letter ended with a single-sentence paragraph that should have set off alarm bells: "As this letter is personal to you, I should be grateful if you could respect its confidentiality."

Yet I never thought for a moment that our foreign intelligence service would be interested in recruiting a person such as myself. After all, didn't it usually approach prospective employees via Oxbridge, using sherryswilling professors as a go-between? Nevertheless, on the assigned date I made my way to an ornate Georgian building on the north side of The Mall, expecting to have a straightforward chat with a career diplomat. I could not have been more mistaken.

My interviewer -in A Spy By Nature he has been given the name Philip Lucas - was an eerily composed man in his mid-thirties, with piercing blue eyes and an unsettling habit of using them to stare at nervous applicants such as myself for long periods. We had a very general, occasionally even stilted, discussion in his sumptuous first-floor office that lasted for about 45 minutes. Then, just at the point at which I felt he was going to draw the conversation to a close, Lucas leant forward in his chair and asked a question that struck me as odd.

"After this initial conversation," he said, "would you like to continue with your application?" The question seemed almost rhetorical, but I nodded and Lucas looked pleased. There had been a file resting on the table in front of us and I was encouraged to pick it up. "I'm going to leave the room for a few moments," he explained, "but before I do so, I would like you to sign the Official Secrets Act."

I stared at the small, nondescript piece of brown paper held in Lucas's hand and felt suddenly catapulted into something adult. In the brief moment that it took to scrawl my signature at the bottom of the page -with no time to check the smallprint -it felt as though the entire direction of my life had shifted. Lucas then left the room and I opened the file.

The first page confirmed what I had by now begun to suspect -that I was being approached for recruitment by the SIS.

What goes through a young person's mind at such a time? I was simultaneously flattered, exhilarated and oddly apprehensive. I was also convinced that Lucas was studying my reaction to these crucial first moments from another room.

There was a small panelled mirror to the right of my chair, solidly framed in gilt so that it looked at first like an antique, but with a very clear, unmarked surface. I had gathered from the layout of the building that there was another room on the other side of this wall. It seemed a certainty that Lucas would be watching me through the glass. Unnerved by this, I attempted to look calm and collected, flicking through the pages until he returned.

When he did so, a few minutes later, I had barely absorbed any of the information contained within the file. Only one sentence had stuck in my mind, if only because I was so amazed to see it there. "Officers," it read, "are certainly not licensed to kill."

Lucas asked whether I had any questions, but it was difficult to think of any: at this vital juncture in the interview, my mind had become a complete blank. To my relief, he embarked on a lengthy description of life in MI6, informing me that an officer's work was characteristically undertaken using our embassies overseas to provide diplomatic cover for running agents.

After 20 minutes, Lucas brought the conversation to a close and told me that he would be in touch. Within three days a second letter arrived, this time from one of his colleagues at the, whom I have named "Patrick Liddiard" in the novel. Liddiard was the Foreign Office man of reputation: impeccably turned out, evidently public school and -perhaps in a case of good cop, bad cop -far more easygoing and charming than his predecessor. After an interview lasting close to two hours, he seemed eager that I should sit the Civil Service Selection Board (or Sisby, as it is known) and I agreed that he could put my name forward.

All prospective SIS officers are required to sit the Sisby, two intensive days of specially tailored intelligence tests, interviews and written papers designed to test a candidate's suitability for a life in the secret world.

I was intrigued to meet my fellow recruits, if only to gain some idea of what the SIS was looking for. What was it, after all, that Anthony had noticed about me to suggest that I might make a decent spy?

Alas, the Sisby provided few answers. The four other candidates with whom I sat the exams were all very different. We were in our mid-to-late twenties and came from a variety of backgrounds: "Matt" was a reticent, scholarly type who looked as though he had never left home; "Sam" was a smooth, articulate employee of a drinks manufacturer, living in Lisbon, who told tall tales about his sexual exploits with stewardesses; "Ann" was a shy, somewhat nervous, young woman from Northern Ireland who had grown up in Belfast and lost an elderly relative to the IRA; and "Elaine" was already an employee of the Foreign Office who claimed to be seeking internal promotion to the SIS (though I suspect that she was planted by the examiners in order to monitor our performance when their backs were turned).

What qualities we shared remain a mystery to me: about all we had in common was the idealism of youth and a sense of honour at being involved in the recruitment process. There were no rogue egos in the group, no Shaylers or Tomlinsons to make one shudder for the future of the intelligence services. If I were to hazard a guess at what the SIS and MI5 are looking for in a spy, I would suggest that it is, more often than not, a person who does not immediately stand out from the crowd. Good spies, in my experience, wear their personalities lightly, are invariably introspective and thoughtful. Furthermore, any suggestion that they are involved in something amoral or corrupt would appal them.

Why, then, was a man such as Richard Tomlinson chosen as an SIS officer? It is illustrative of his vanity that in his memoirs, The Big Breach, Tomlinson claims to have been employed because of his superb mental and physical prowess. Certainly he impressed the SIS examiners, yet even then they claim to have had concerns about his mental stability. Tomlinson was apparently given a job only because the SIS was desperate to find officers with sufficient expertise to understand the increasingly technical nature of its intelligence reports. He had graduated from Cambridge with a first in aeronautical engineering, and was therefore too good to pass up. How the SIS must regret that decision.

My own vigorous encounter with the SIS ended shortly after the Sisby. I had become convinced that it was the wrong career for me -and the SIS had arrived at more or less the same conclusion. In A Spy By Nature, the central character, Alec Milius, receives a phone call from Liddiard informing him that he has failed to make it through to the next stage of recruitment. He is distraught, though his experiences in the intelligence world are only just beginning: he takes a job with a British oil company and soon finds himself involved in the murky world of industrial espionage.

I, on the other hand, decided to turn my experiences into fiction, perhaps to the irritation of those at the SIS who had given me such an extraordinary opportunity. The first section of my book does indeed break the spirit of the Official Secrets Act, but not, I am convinced, in a way that would undermine the intelligence services.

As an old teacher of mine used to say: "Laws are for the obedience of fools and the guidance of wise men."

AT THE start of Charles Cumming's novel, A Spy By Nature, a young man named Alec Milius finds himself sitting in an ornate Georgian building near the Mall being interviewed for a job by MI6. Although the book is strictly a work of fiction, this first section draws extensively on Cumming's own experience of being approached for recruitment by the Secret Intelligence Service

IT was 1995. I was 24 years old and had graduated from Edinburgh University with a good degree in English literature. Like so many of my contemporaries, however, I had no idea what I wanted to do with my life.

An answer presented itself at a dinner party hosted by my mother in February, at which I met a man - let's call him Robert - who told me he had "recently retired from the Foreign Office".

We got on well and several days later he contacted me asking if I would be interested in applying for a position "within the diplomatic service".

Flattered to be asked, I agreed enthusiastically and assumed that Robert would put my name forward for a desk job at the Foreign Office. He told me to expect a letter in the post within the next few days.

It duly arrived.

Written on official Foreign and Commonwealth Office paper, the letter invited me to an interview but its final sentence should have set off alarm bells:

"As this letter is personal to you, I should be grateful if you could respect its confidentiality."

My interviewer, given the name Philip Lucas in my novel, had the clearest, most penetrating eyes I had ever seen. We initially talked for about 45 minutes before he asked me a question which struck me as odd.

"After this discussion, " he said, "would you like to continue with your application?"

I nodded and Lucas seemed pleased, handing me a file. "I am going to go out of the room for a few moments, " he explained. "But before I leave I would like you to sign the Official Secrets Act."

It took no great powers of deduction to realise that I was now involved in something beyond the normal scheme of things. I scrawled my signature on a nondescript piece of brown paper, tried to disguise my anxiety and opened the file. Lucas then left the room.

The first page confirmed that I was being approached for recruitment to the Secret Intelligence Service. I felt simultaneously exhilarated, humbled and oddly apprehensive. Just as quickly, however, I became convinced that I was being watched from another room.

There was a small panelled mirror to the left of my chair, solidly framed in gilt so that it looked at first like an antique, but with a very clear, unmarked surface.

I knew from the layout of the building that there was another room on the other side of the wall and was certain that Lucas was watching me through two-way glass.

Attempting to look settled and businesslike, I flicked through the file and waited for him to return.

When he came back a few minutes later I struggled to think of any questions to ask him, and was relieved when he embarked on a lengthy description of the life of an SIS officer.

After half an hour he brought the discussion to an end and told me that he would be in touch. Within a matter of days another letter arrived, this time from one of Lucas's colleagues, whom I have named "Patrick Liddiard" in the novel.

Liddiard was the Foreign Office man of reputation - ex-public school, very warm and charming, and he seemed eager that I should sit the Civil Service Selection Board exams as soon as possible. Since the dark days of Burgess and Maclean, all potential employees ofMI5 and SIS have been required to sit the same exams as ordinary members of the public heading for a career in the civil service.

However, prospective SIS candidates undertake a tailored series of interviews, IQ tests and exams - nicknamed Sisby - designed to test their suitability for a life in the secret world.

I have often wondered what qualities Robert, Lucas and Liddiard saw in me to convince them that I would have made a good spy. Certainly the four other candidates with whom I sat Sisby seemed to have very little in common.

We were all in our mid to late twenties, but came from a variety of backgrounds. "Matthew" was a shy, nervous academic studying European law at Warwick University; "Sam" was a very likeable, impressive employee of Rothman's tobacco, living in Saudi Arabia, whom I have perhaps unfairly portrayed in A Spy By Nature; "Ann" had grown up in Northern Ireland and lost a relative to the IRA at Enniskillen.

The fourth member of the group, whom I have called "Elaine" in A Spy By Nature, was already an employee of the Foreign Office who claimed to be looking for internal promotion to SIS.

Somehow this didn't ring true.

To this day, I remain convinced that Elaine was "planted" in our group by SIS in order to monitor the performances of the other candidates when the judges ' backs were turned.

In the wake of recent scandals in the press, it has often been asked how men such as David Shayler and Richard Tomlinson were ever allowed to walk the hallowed halls of MI5 and MI6. On what basis does British intelligence recruit its employees? The answer, at least in Tomlinson's case, is straightforward. At the time of his recruitment, SIS were desperate to find officers with the right technical expertise to understand the increasingly scientific nature of its intelligence reports.

Tomlinson had graduated from Cambridge with first class honours in aeronautical engineering, and therefore fitted the profile perfectly. He may have believed that he was handpicked because of his dashing good looks and searing intellect, but the truth was rather more mundane.

Yet intelligence organisations around the world will certainly take advantage of a candidate's youth and relative inexperience.

The graduates whom MI5 and SIS target often feel flattered to have been approached for such prestigious work. At the age of 23 or 24, a young person can have little or no idea of the effect a life of secrecy and guile is going to have on them, or on their friends and family.

My SIS interviewers harped constantly on the notion of serving the State. In Britain the idea of "Queen and Country" used to guarantee a certain kind of loyalty, a loyalty which does not ask awkward questions.

But there are fewer and fewer candidates nowadays who are prepared to think in these terms.

Furthermore, it does not help that the starting salary for an SIS officer, at least when I was approached, was less than GBP 20,000 a year.

Why take a job in the intelligence world when you can earn three times as much in the City?

If MI5 and SIS have a recruitment problem, it may stem from some of these issues. The perceived glamour of spying needs to be stripped away.

Otherwise, for every loyal servant of the State suited to a career in the secret world, there will be a Shayler and Tomlinson who, having expected to bask in the reflected glory of being a spook, become embittered when they discover that the job is actually rather mundane.

My own vigorous encounter with SIS came to an end after the selection board. I had become convinced that it was the wrong career for me, and SIS had arrived at the same conclusion.

In A Spy By Nature, Alec Milius receives a phone call from Patrick Liddiard informing him that his candidature will not be pursued any further. Milius is distraught, although his experiences in the intelligence world are only just beginning.

I, on the other hand, was relieved to be free of the responsibilities required of an intelligence officer. With the benefit of hindsight I can see that a career in SIS would have robbed me of many of the freedoms that we take for granted.

It takes a very particular person to commit themselves to such a life: an unarguably brave and idealistic upholder of British values prepared to disappear into a clandestine world. It is not the fault of SIS that candidates of this sort are in short supply.