By her own admission, Taylor was often in trouble. Chewing in class, back-chatting, generally messing about, hers was the sort of low-level disruption that can drive teachers to despair. “I was getting taken out of class all the time,” she says.

Things are different now, though, and Taylor is in no doubt of the reason. She credits joining the school’s combined cadet force (CCF) for her decision to stop mucking around. “I don’t do it now because I’m in the CCF,” says the 13-year-old.

Her school is one of a small but growing number of state schools to run its own cadet force. Traditionally seen as the preserve of independent schools, cadet forces aim to give children a taste of military life, but have also been championed as a way of improving relationships between the public and the armed forces, and for helping instil discipline.

Every Wednesday afternoon, the 75 cadets at Thomas Deacon Academy in Peterborough assemble in uniform for their weekly training. Sessions include drill, map and compass, field craft, skill at arms, camp craft and first aid. They will also go on at least three weekend camps a year and a week-long camp during the summer term.

Today’s session is drill, and involves marching in formation followed by crouching on the school field with wooden rifles, although the cadets also get to handle real weapons and fire live ammunition.

“You get to do a lot of things you wouldn’t normally do,” says Natalie, 16. “It’s confidence building and you feel more self-reliant.” There’s also the traditional armed forces’ emphasis on turn-out: cadets have to look smart. “I do a lot more ironing now,” says 14-year-old Amber.

Thomas Deacon was one of six state schools chosen by the Ministry of Defence to run their own cadet forces in a three-year pilot beginning in September 2007, coinciding with the opening of the new academy. The following September the Government announced that pupils at a further six state schools would get the chance to join CCFs run by neighbouring independent schools.

Announcing the partnership scheme last year, Andrew Adonis, then schools minister, said cadets were “a force for good” in schools, promoting confidence, resourcefulness and a sense of service to others. Gordon Brown has supported military training in schools and last year a government- backed study said more state school pupils should be encouraged to join the cadets as a way of improving public recognition of the armed forces.

Alan McMurdo, principal at Thomas Deacon, is a firm supporter of cadet forces after seeing them in action as a member of the senior management team at two previous state schools. “I have seen what it does for kids,” he says. “It is an opportunity they would not normally get and they have the chance to try things in a disciplined environment.”

He says the cadets help develop leadership skills, promote teamwork and boost self-esteem. The school also runs a Duke of Edinburgh award scheme, but Dr McMurdo says that as well as offering an insight into military life, the CCF differs in being a more structured and regular programme. CCF members can also qualify for the Btec diploma in public services, the equivalent of up to four GCSEs.

At its annual conference last year, Voice, the teachers’ union, backed the creation of cadet forces in every school as a way of instilling self- discipline and improving classroom behaviour. But not everyone is keen on the idea of the military in schools. The NUT voted last year to oppose recruitment based on “misleading propaganda” by the armed forces in schools, and the Educational Institute of Scotland, the largest teaching union north of the border, has called for army recruitment teams to be banned from visiting schools and colleges.

But Dr McMurdo, himself a former Royal Navy officer, rejects suggestions the CCF is about encouraging children to enter the military. “It’s not a recruitment drive at all,” he says. “It is giving youngsters experiences for them to make their own judgment.” He has seen children go into the military who were never in the CCF, and children in the CCF who were never interested in a military career.

He believes the opportunities the force offers are particularly important for children in the sort of deprived communities served by Thomas Deacon, who would otherwise never get the chance to go kayaking or camping.

He says while discipline is an important part of the CCF, it would be wrong to see it as a way of bringing children into line. “It does make a difference at a whole school level, but we’re not sitting here thinking the CCF is going to sort out behaviour problems for us. That is not the main reason we’re doing it.”

For children in the cadet force, the spin-off into the rest of their school lives is not just about behaviour. “My school uniform before was a bit untidy, I used to walk around with my top button undone. Now it is perfect,” says Richard, 16. Holly, also 16, says she has become more organised and her time management has improved.

And changes in behaviour are not just down to military codes. Like Taylor, Amber is no longer regularly taken out of class. She also gets up early to make sure her uniform is in good order. Part of the reason, she admits, is that she is “slightly scared of Mr Thompson”.

Chris Thompson, PE teacher, is commander of the school’s CCF contingent, with the rank of captain. He spent 12 years in the Army, the Worcestershire and Sherwood Foresters, an infantry regiment now amalgamated into the Mercian Regiment, where he was a sergeant. He says discipline is a cornerstone of the CCF. Cadets know that when they are in uniform, which is all day on Wednesdays including during regular lessons, they are seen as members of the CCF. Pride in the uniform is a powerful incentive to behave, and he says this is rubbing off on other pupils. “There is an ethos of discipline, and that changes the fabric of the school,” he says.

There have been hiccups. He says there was an initial tendency for teachers to use the threat of expulsion from the cadets as a sanction. This made cadets vulnerable in a way other pupils weren’t. “You wouldn’t say `if you don’t stop that I will kick you out of English’,” he says. “It should be a carrot, not a stick.”

Thomas Deacon was given a grant by the Ministry of Defence to set up its cadet force, paying for uniforms and the hut that serves as the CCF headquarters. The regular Army also provides support and training, and pays the staff involved, but there is still a cost to the school in staff time and funding some activities and camps. The school runs it on a cost neutral basis, with cadets paying a Pounds 20 a term subscription.

The financial and staff requirement is one reason the school’s CCF is limited to 75 pupils, from the original 120 who applied, although this September Mr Thompson will start a 25-strong Royal Air Force section. As with its Army section, recruits will be required to complete an initial period of training before they are accepted and issued with a uniform. “We should have areas where we say people didn’t pass and they should come back and try again,” says Mr Thompson. “It gives them a sense of achievement when they do make it.”

He says there has been a visible change in the pupils who made it into the CCF. “You can see it in everything from self-confidence to how they hold themselves and how they talk to people,” he says.

They may have initially been a source of curiosity, and even ridicule, but any embarrassment or defensiveness over wearing the uniform has long since disappeared. “You feel quite special walking around,” says Holly. Natalie adds that while it was strange at first, now everyone is so used to it that seeing the uniforms around school is “not a big deal”.

Dr McMurdo says in the 20 months since its creation, the CCF has become a key feature of the school. “The kids who love it absolutely flourish and their personal development is staggering.” He says emphasis on leadership skills in particular has encouraged cadets to take on more responsibility, which has spilled over into the rest of their lives. “For a lot of our youngsters it is what they need, and when they come to school in their uniform it sends out a message to the rest of the school and to our community at large that this is part of what we are doing.”

While not everyone is comfortable with the idea of children in uniform, for the cadets themselves it is a source of great pride. And if the pupils at Thomas Deacon are anything to go by, it is helping keep them in the classroom as well.