The Vatican City may be the heart of Catholicism but as anyone who has ever been there knows, it is also the centre of a thriving and ruthless tourist trade. This is nothing new pilgrims have meant big business for hundreds of years.

The hard sell starts on the Ponte S. Angelo leading to Castel S. Angelo where street vendors flog fake Prada and Fendi bags. It continues on Via della Conciliazione, which leads up to the basilica, with tourist shops selling a multitude of guidebooks, postcards and kitsch paraphernalia. Mobile stands sell overpriced snacks, street sellers proffer rosaries and other trinkets, restaurant staff hand out fliers, and dozens of English-speaking tour guides pitch visits of the basilica and the Vatican museums.

As these guides and their gatherers (people who collect groups for the guides) roam around Piazza S. Pietro and whats left of the mediaeval Borgo, their pitch typically begins with the words, Do you speak English? If they get a flicker of recognition, their next line is: Would you like to join an official tour of the Vatican museums starting in 15 minutes?

But in truth there is probably nothing official about the tour since most English-speaking guides are unlicensed and many of them work for companies that are not legally registered. To make matters even more precarious, many of the guides from north America and other non-European Union countries are illegally resident in Rome.

Alternatively, the guides invite tourists to join a free tour of the basilica. The tour is indeed without charge but always ends with an invitation to go on a paying tour of the museums, demonstrating the truth of that timeless adage, you cant get something for nothing.

Diana, who has helped manage a Rome-based tour company for the past two years, believes that free tours cause endless trouble. With tours going on in dozens of different languages every day, the noise levels in the basilica were becoming really disrespectful she says. A new rule introduced at the beginning of September has helped to tackle the problem by obliging tour groups of more than three to use a so-called whisper system in the basilica whereby the guide speaks through a microphone and the people in the group wear headphones.

A knock-on effect of the new rule is that it has reduced the number of unlicensed guides doing free tours and weeded out the mediocre ones, adds Diana, because booking the audio-guides in advance, picking them up and paying for them has added time and cost to the set-up process.

Since the introduction of the new rule, the legally-registered company which Diana works for has started handing out fliers advertising its tours, as a way to set itself apart from its unlicensed competitors. As a promotional tool, Diana says that this works as well as, if not better than, free tours.

Luisa is a licensed guide and has been doing tours of Rome and the Vatican in Italian, English and French for the past 13 years. She says the concorsi (competitive exams) to become a licensed guide are held more frequently now, so there isnt any excuse not to get a licence. All professions have a register lawyers, doctors, and so on, where the state gives you a qualification proving you have the ability, skills and experience to do the job. She continues: I have seen people without licences who are really good, but the majority of them are not. Only the exam can guarantee the professional level of a guide without it the customer is taking a risk.

Ironically, Luisa, like many other official guides, started out without a licence. She explains that this was because there were no exams held between 1989 and 1999. Since then, an exam was held in 2002 and the announcement of another is expected by early next year. The reason the date is not yet confirmed is because running the test is a political decision, according to an assistant in the provinces competitions office.

This will-there-wont-there enigma surrounding the exam is what riles many unlicensed guides keen to legalise their situation, and leads some of them to think that there is a vested interest in their not getting a licence. One says: Many of the older licensed guides are not very dynamic and are scared we will take work away from them. This particular guide may have more reason than most to feel embittered after being punched in the chest earlier this year by a licensed guide who wanted her out of the way.

John, an American guide who works for a legally-registered company but is unlicensed, speaks of the stress provoked by the constant but random checks by Vatican police, many of them undercover. He says that all the guides he works with abide by an unwritten set of rules, such as not poaching people from other tour groups.

Unfortunately, not all unlicensed guides are so considerate, for example those who come to Rome for a couple of months in the summer and give the unlicensed arm of the profession a bad name. One such guide was seen leading a group of 72 people, which is just awful remarks John incredulously.

Yet even though Luisa understands the plight of unlicensed guides, she counters that many make serious presumptions about how hard the exam is, deriding the system as byzantine and claiming it is a closed shop to foreigners. On the contrary, there is no limit to the number of people who can take the exam, she says, and in so far as difficulty is concerned, she explains: You are asked to know about painting, art, archaeology and history of art. If you dont pass the exam, it probably means you are not qualified to carry out this profession. On a slightly tougher note she adds: These guides want to explain things about our culture and society, but they dont want to respect our laws.

All names used in this story have been changed as both the licensed and unlicensed guides interviewed requested not to be identified.