Royal approval: How Michael Gove is taking lessons from the Prince of Wales

The influence of Prince Charles's annual summer school is growing.

Next week, 120 eager English, history and geography teachers will convene in Cambridge to refresh their brains with four days of high-level lectures in an event that has become as much a part of the school calendar as SATs tests and Christmas concerts.

They will listen to the new Education Secretary Michael Gove talk about his plans for revising the curriculum. They will also see the playwright Tom Stoppard and the historian Michael Wood, take a drama workshop with the Royal Shakespeare Company. They will join in seminars and workshops and gather over drinks and dinner to decry an education system that makes them to tick boxes and meet targets and which elevates the acquisition of skills over the passing on of concrete knowledge.

Eight years ago, the first Prince of Wales Education Summer School was founded to help teachers "rediscover the love of their subject", but drew fire for being doctrinaire and elitist. Set up with the help of independent school heads and championing traditional history, the newspapers dubbed it Prince Charles's attack on "trendy" teaching, causing critics to say he had no business poking his nose into the classroom.

This year, The Prince's Teaching Institute, as it is now called, will be running its summer school at Homerton College, secure in the knowledge that its power base is growing and the educational climate is swinging its way.

Not only has Michael Gove praised it and asked for input on his planned revision of the school curriculum, but its long-standing campaign for children to be taught history as a national narrative – as opposed to random dips into Hitler and the Henrys – has prompted curriculum changes and moved it into the mainstream.

Teachers queue up to get places on it, and the institute has expanded its role from its original focus on English and history into supporting geography, maths and science teachers, running one-day workshops, organising conferences for heads and managing a growing network of schools that can use the Prince Charles royal feathers on their writing paper as part of his schools network, owing to their commitment to subject teaching.

"The institute has always been run by teachers for teachers," says Bernice McCabe, head of the independent North London Collegiate School and director of the summer school. "We wanted to give a voice to the profession, and the sorts of things we talk about in the summer schools are designed to enrich teachers and enhance their enjoyment of their subject. The schools programme has been set up so that they can take something back into schools."

According to enthusiastic advocates, the institute is filling a big gap in the teacher training market. Gareth Davies, lead teacher for gifted and talented -students at Sawtry Community College, in Cambridgeshire, only got involved because an invitation in his school pigeon hole offered him the chance to hear the poet Seamus Heaney. But he has since been a teacher leader at five summer schools.

"These schools remind you of the joy of being taught well. Usually, professional development courses for teachers are either a guy in a blue shirt and chinos and a PowerPoint presentation talking about learning skills or someone from a commercial company spouting the latest crop of educational initials. This is about reconnecting with what got you into teaching in the first place. You'll never get a kid come up to you in the street and tell you they remember that worksheet, but they will tell you they remember a poem."

Catherine McCrory, head of history at Sweyne Park School, in Essex, and a teacher trainer at Anglia Ruskin University, says the institute addresses two gaps in teachers' subject training. The summer schools are there to enrich individuals. "There's a wonderful vibe, you get back your enthusiasm for the subject, and it reminds you what it feels like to be learning something new – it's important for teachers to remember that." And the grassroots networking keeps that fire going. "In our region, we have a yearly meeting, there are 10 history departments represented and we sit down and talk about what we feel we do well. It's all about the quality of the ideas and new ways of thinking." She has introduced local speakers to her students and linked up with the historical society of a local girls' high school.

But Prince Charles is a complex character and many teachers remain suspicious of his motives. Davies admits that when he turned up to his first summer school, he was full of doubts about something with the Royal name attached. These doubts derive from the fact that many of the institute's champions have come from what the historian Tristram Hunt, now Labour MP for Stoke-on-Trent Central, has termed the Prince's "circle of conservative cronies". Former chief schools inspector Chris Woodhead and columnist Melanie Phillips have advised him on education, while right-wing historians such as David Starkey and Andrew Roberts support his work. "I think the debate is good and the summer school is good," Hunt says. "But there's an intellectual context that is just not agenda-free."

These days, those fears are still there, although McCabe points out that the institute is backed by all political parties, and has hosted speakers of all persuasions. She energetically swats another prejudice – that the institute is only for private school teachers, or those teaching academic courses. "Our delegates come from all school backgrounds," she says. "There's no reason why you shouldn't have a rich curriculum in a school with challenging social circumstances. The institute is run by passionate teachers who believe you shouldn't patronise pupils by thinking they can't be taught serious stuff. We're the opposite of elitist."

Former critics grudgingly agree the summer school has a place in the educational landscape. "Anything that looks at improving teachers' subject knowledge has to be a good idea," says Ian McNeilly of the National Association for the Teaching of English. "After all, it's what we do for a living, all day, every day – although, of course, the difference is to do it without that backing and wealth."