"Don't jump on the bandwagon." This is the advice that life-coach guru Fiona Harrold has been giving to the hundreds of former counsellors and psychotherapists who have come knocking on her door, hoping to rebrand themselves as life coaches. "I refuse them," she declares. "I say, 'You're a psychologist and that's a great thing.' I see so many book jackets now where five years ago the authors called themselves a psychologist and now they are a coach. It makes me laugh."

Life coaching is the biggest growth area in the self-help world. As dysfunctional coaching- convert Warren crowed recently in This Life Plus Ten, the industry is worth an estimated £50m a year and rising. Life coaching is "where it's at".

The concept is largely accredited to Thomas J Leonard, who founded a training centre called Coach U in Arizona in 1992. Two years later he set up the International Coach Federation and the idea went global. The London-based Coaching Academy, the UK's biggest coaching school, has trained 10,000 new coaches over the past seven years, and the Association for Coaching, also based in London, aims to pull in 2,000 members by the end of the year.

Becoming a coach or, as some prefer to be known an "agent of change" is, in fact, a doddle. The industry is unregulated and no genuine qualification is needed, so anyone can decide to become a life coach, quite literally, overnight. And the incentive to do so is there. "Agents" can charge anything from £30 an hour to thousands of pounds a day. "Of course, some people will come to it thinking that it is an easy way to make money," says Harrold, whose own book on the subject, Be Your Own Life Coach, has sold millions of copies.

One estimate puts the number of life coaches currently practising in the UK at between 80,000 and 100,000. Oddly enough, another figure is bandied about, too: that 100,000 Britons used a life coach in 2005. This works out as one life coach per client, which sounds about right. Many online testimonials reveal that many only decide to become coaches after having been coached themselves. But none of these statistics are official. Because there is no official life coaching body, the numbers are impossible to verify.

January is life coaching's busiest time of the year, with thousands of recruits signing up for help with their New Year resolutions. But the executive and corporate sector is still the most lucrative. Specialised coaches offering mentoring services to top-level execs can earn as much as £10,000 a day. Last year, it was reported that Patricia Hewitt and other cabinet ministers use £250-an-hour life coaches to "cope with the pressures of government". No 10, the Home Office, the Foreign Office, the Cabinet Office, the Department for Transport and the Treasury have all used coaches, or "critical friends" as they preferred to be known in this particular case.

"What you realise talking to senior business people and executives is that everybody has them but no one wants to talk about it," says one high-profile London-based businesswoman, who keeps in touch with her American coach by phone. "I've had a number of lunches where I've mentioned it. People lower their voice and admit they have one, too."

A small group of charismatic life-coach gurus including Harrold, now practically a household name thanks to her book and appearances on Channel 4's Faking It, are skilled at inspiring others. She started out as a "self-esteem consultant" more than 20 years ago. This group would do what they do whatever it was called and regardless of whether it was trendy and there was money to be made from it. But then there are all the rest. "Coaching is unregulated so you are at the mercy of whether it's crap or not," says the businesswoman. "A lot of it relies on you using y0ur own skills and judgement."

Why do they do it?

Which begs the question: why do people need to visit a life coach? According to the "experts", people who need coaches are those who are not satisfied with the status quo or who want to feel differently about their future. They might be seeking clarity and resolution, evaluating their career options or facing difficult choices. Almost all will have some sort of anxieties or relationship concerns. Most will want to gain deeper self-understanding and acceptance. So, that's pretty much everyone, in one way or another.

Getting a helping hand with public speaking to boost your chances of climbing the next rung on the corporate ladder is one thing. But experts in psychology are concerned that vulnerable people are not receiving the treatment they need. Phillip Hodson, fellow of the British Association for Counselling and Psychotherapy, believes that coaching can never be effective unless coaches train in some form of therapy. "Life coaching uses a model that is contradictory to most established psychotherapies. It is goal-focused not client-centred. It addresses symptoms rather than causes." This creates not only a risk for the patient but a public risk as well. "After all," he argues, "there is the issue of personality disorder. How on earth are you going to recognise one if you don't know what it is?" Frank Furedi, professor of sociology at the University of Kent, has also spoken out against life coaching as intrusive and a waste of money, observing that: "There's a growing idea that human beings lack the competence and resources to cope with everyday life."

All this won't stop it from growing, however, says Hodson. "As a society we are now ready to address the question of our alienation but we don't really want the answers to hurt. It's like wanting to do your bit for climate change but keeping the 4 x 4." He adds the killer blow: "If the power of positive thinking could solve all our problems we wouldn't have any."

Harrold dismisses this out of hand. "People want results and why shouldn't they be given the tools to get them?" she says. "People don't want navel-gazing. They want to be able to walk into the office tomorrow and get a promotion."

Life coaching explained

So what is it?

"A collaborative solution-focused, results-orientated and systematic process in which the coach facilitates the enhancement of work performance, life experience, self-directed learning and personal growth of the coachee." Anthony Grant, University of Sydney, 2000.

How is this different from traditional therapy?

Life coaching looks to find solutions to the problems rather than to solve the causes. Coaches encourage their clients to use "cognitive techniques" - aka, thinking - to unlock the key to success.

What qualifications do life coaches have to have?

None. Anyone can become a life coach. But many reassuringly cite their years of experience in "human potential".

Who needs a life coach?

According to the experts themselves, just about anyone who is cheesed off with any part of their life.

With no professional body to regulate, how do you know which coach to choose?

London-based life coach Sally Ann Law, one of the first coaches listed on Google, has sound advice. "Absorb all the information available to you," she says on her website, "then listen to your heart and your head about whether you think this person appears credible and empathetic." So as long as decision-making isn't your problem, you should be OK.

How can I find out more about life coaching?

Another pearl from Law. Try an internet search, she suggests. "Enter 'life coach' and you'll be inundated with options."

How much does it cost to become a life coach myself?

Anywhere between £700 and £3,000

How much does a life coach earn?

Well, logic suggests success. Top earnings are thought to be £10k a day.

Sohani Crockett