In all my years as head, this is the first, commonsense, practical help towards helping us crack the unique educational problems we face.” So says John Troake, head of Haling Manor secondary school in Croydon, about what is possibly London’s most secret good-news story - the Keys to Success scheme.

While London Challenge, the five-year programme launched by Tony Blair in 2003 to improve the lot of teachers and students in the capital is already familiar, one of its most exciting strands remains - inexplicably - in the shadows.

It was set up to help some of the most challenging secondaries in the country and uses as a resource many of the features which make London a tough place to teach, arranging contacts with other schools and support from heads who have overcome major difficulties.

The scheme gives leaders of struggling schools support rather than stick in tackling problems. At its heart is a direct link between individual heads and their own Keys to Success adviser, who can fast-track resources - the scheme has a pound;3 million budget - direct from the Department for Education and Skills.

In keeping with its name, the scheme is showing signs of great success. In 2004, London exceeded the national average for GCSE pass rates for the first time, and was rated the fastest-improving region in England. By 2005, the results of Keys to Success schools - spread across London’s 33 boroughs and including some of the country’s toughest secondaries - had improved by an average of 5 per cent a year since the start of the programme.

Between 70 and 75 of the 204 London secondaries are in the scheme at any given time. So why do the people involved seem to be dismayed rather than pleased by media attention?

In fact, many feel they are picking their way through a minefield of sensitivities. Success depends on the co-operation and trust of the school leaders involved, who are used to reading headlines about anarchy in their schools and the declining quality of state education in the capital. They felt that the last thing a beleaguered head struggling with budgets, staffing and student problems needs is the glare of negative publicity.

“This is extremely sensitive work,” says George Berwick, who co-runs the scheme’s consultant leader programme.

“The term Keys to Success can be perceived as a deficit model, but we are actually working with good heads in very challenging situations. If the bonds of trust we have built up with them are broken, it undermines everything we’ve achieved so far.”

Schools join the scheme in a variety of circumstances. Some may have been in special measures and seen membership as a way of climbing back out.

Others have been approached by their local authorities or one of the 11 advisers in the scheme.

Kate Myers, an adviser for the boroughs of Haringey and Croydon, says involvement is always voluntary.

“This is a partnership programme,” she says. “We all agree that we are not inspectors. We build up trust with our school and then act as critical friends.”

David Woods, senior adviser on the scheme, says schools and local authorities were wary in the early days and suspected yet more interventions and directives.

What made Keys to Success different, he says, was that it was not another “one size fits all” scheme dropped on to already overloaded heads.

“We are offering a menu of support to pick and choose what suits best, so that each programme is individually tailored in partnership with the head,”

he says. “The adviser’s line of reporting - straight back to the DfES - means we can act very quickly.”

Professor Myers agrees. “It’s very important that the programme is different for each school,” she says. “For a school with a very high number of children whose first language is not English, for example, we can organise visits to another school with a large ethnic intake to see what work they are doing.

“If there is a lack of capacity in the leadership team, we can bring in a temporary deputy to give the head extra support.”

The beauty of the scheme is its “power to cut through the crap”, as one head puts it - its flexibility and a belief that with the right support, heads play a vital part in solving their own school’s problems. Often, says Dr Berwick, heads in difficult schools can spend so much energy on fire-fighting that they have no space to plan strategically.

“We’re there to make the head’s job easier,” he says.

For Mr Troake, this is a sea-change in attitudes. “There has traditionally been inspection overload when government has wanted to know why pass rates weren’t better,” he says.

“Then there’d be lots of talking around the subject and a culture of short-term fixes, but no strategic view. Keys to Success was a breath of fresh air.”

Mr Troake, who works closely with Professor Myers, says Keys to Success is the best initiative he has seen in his 11 years as a head.

“Kate is challenging, but she comes up with answers too - and targeted resources,” he says. “There’s no dithering about. I can tell her I need something on the phone before she gets here, and if the DfES hasn’t called me to arrange it by the time she arrives, she wants to know why.”

But benefits are not all one-way. Consultant heads, carefully recruited according to their experience and success in Ofsted inspections, work with their client schools one day a week and often take away new ideas.

“Traditional collaboration was a hit-and-miss affair with competition often creeping in,” says Dr Berwick. “Here, schools are so far apart that there can be no competition. Both sides are improved by working together. It’s a case of saying, ‘Let’s make both our schools better.’”

Paul Grant, head of Robert Clack school in Dagenham, east London, and a consultant leader, agrees. “Most schools have some virtues, even in extremis - so it’s a two-way relationship,” he says.

“What’s really exciting about the London Challenge and Keys to Success is the way a community of schools has been created. It’s a London solution to a London problem.”

Mr Grant’s school “started from a very bad place” and has built impressive results on engaging its tough, working-class pupils. Keys to Success allows it to share its experience with the many London schools facing similar challenges. Others may offer ways of working with, say, diverse, multi-cultural school communities or disadvantaged children.

Yet success is not ubiquitous. The impact of the scheme has been largely dependent on the effectiveness of the adviser allocated to each school, and this has varied. Also, there are heads in the scheme, says Mr Troake, who still feel it is one more case of initiative overload. But the overwhelming verdict half-way through the scheme’s life is positive.

When Keys to Success ends in 2008, it should leave London’s toughest schools with new resources to cope with the challenges of the metropolis.

“One turn of the Keys to Success will be the schools that can go on to become academies,” says Mr Woods. “The other will be those that can stand and compete on their own feet.”

Those involved believe the most precious legacy will be the strength that comes from community and shared expertise.

“Now we are good,” says Dr Berwick. “By 2008, we’ll see an even stronger return on what we’ve done. By the Olympics in 2012, this should be the best urban education service in the world.”