When teachers from Hounslow Heath Infant and Nursery School in Middlesex took 30 banner-wielding six and seven-year-old pupils to Westminster to protest against plans to expand Heathrow airport, the children were resolute.

The allocated speakers, who had to be lifted up to a microphone, told the audience that they didn’t like the amount of noise the planes created and that they couldn’t hear their friends speaking when they flew over.

“I was impressed by the children. They seemed to understand what they were saying,” says Kathryn Harper-Quinn, the headteacher. “Normally I would not advocate using young children in campaigns, but we’re talking about their future. And it’s clear to me that they understand what they’re campaigning about - aircraft aren’t subtle things, so it’s not a quantum leap, even for a small child,” she says.

The west London school lies under the flight path for the airport and Ms Harper-Quinn has been campaigning against expansion plans since 2002. She and other campaigners argue that up to 100,000 children at 114 schools will have their education blighted even further by noisy aircraft if the expansion goes ahead.

But should schools encourage pupils to become activists at such an early age? Not all schools are willing to do this, either because they fear repercussions or feel it is inappropriate to involve the school in political matters that the children might not understand, particularly in the case of primary schools where encouragement might be perceived as indoctrination.

Yet a growing number are involving pupils in some form of campaigning. Those that do point to the knowledge and skills a child can gain from the process, as well as the benefits a campaign can bring for the school and its wider community.

The emergence of school-based campaigns can be attributed in part to the introduction of citizenship education on the curriculum in English schools in 2002. Teaching of the subject, which has been compulsory in secondary schools since then, is based on the premise that citizenship is inherently active - that pupils can only really learn about democracy and participation by being encouraged to play an active role in school and society from an early age.

The programme of study in secondary schools focuses on increasing political literacy, developing the skills of debate and inquiry and encouraging active participation. Pupils do not have to sit a GCSE exam in the subject, but the number of pupils that did last year rose to 84,588 entries - up nearly 17,000 on 2007, according to the Department for Children, Schools and Families (DCSF). And although many primary schools do cover it, it is not a requirement for them to do so.

Tony Breslin, chief executive of the Citizenship Foundation, the subject association, stresses that the aim of citizenship is to build pupils’ political literacy and engagement, not one or the other.

“Many schools do a good job of embedding citizenship in the curriculum but could do better at encouraging pupils on the participation side. Others do the opposite,” he says.

Schools that manage to achieve both are referred to as being “citizenship- rich”. They tend to benefit from stronger academic performance and reductions in exclusions, adds Mr Breslin. But only about a third of schools in England are considered to have achieved this status, according to the National Foundation for Educational Research’s (NFERs) most recent figures, from 2007.

Whether in or out of school, pupils are becoming increasingly savvy on a range of social issues, particularly the environment. Staff at Argyle Primary School in the London borough of Camden, for example, believe so firmly that children benefit from being engaged from a young age that they’ve embedded citizenship and sustainability throughout the school’s curriculum.

Even in early years education, pupils are involved in practical work, looking after their environment. The older pupils are encouraged to campaign, raise funds and boost awareness on issues they help choose. Year 5 pupils, meanwhile, write campaign letters to governments in other countries as part of geography lessons on rainforest destruction.

Children are encouraged to develop a sense of responsibility, fairness and commitment and the school’s website boasts that they “engage with their world, believing that they can and should make a difference where necessary”.

Some schools choose to focus on hard-hitting issues that are closer to home. Pupils at Gladesmore Community School in north London chose to campaign against gun and knife crime. The school is situated in an area where this is a problem, so it’s likely to have touched the lives of the pupils’ friends and families.

The school’s citizenship department came up with a campaign called Value Life in 2004. When it started, it had just nine student members, but now boasts the entire student body.

They run the campaign through the student council, meaning they decide what they want to do and how - ranging from peace walks and rallies to the production and distribution of DVDs for other schools.

Teachers maintain an element of supervision as the project is overseen by the school’s head of citizenship studies and PSHE, Lee Carryl. With the help of the wider school and a steering committee, they make sure the implications of what the group plans to do are considered and viable. The group’s annual marches, for example, attract more people each year, with 1,200 people expected to attend the next one.

Some members of the group also get involved in activities at a higher level. Valerie Okoampah, a senior school council representative, gave evidence at a Home Affairs committee meeting on tackling knife crime earlier this month, where she met and gave advice to Jacqui Smith, Home Secretary.

For Mr Carryl, the benefits for pupils, the school and the wider community as a result of the introduction of citizenship studies and the Value Life campaign are plentiful. “Since the introduction of the subject there has been increased pupil participation in campaigns around the school and democratic engagement, with pupils taking part in elections, such as for the school council and UK Youth Parliament.”

He continues: “Pupils get a great deal from organising and participating in Value Life. It’s empowering because they get an opportunity to campaign about an issue that affects their lives and try to find meaningful solutions. Pupils have an opportunity to get their voices heard by senior decision makers. It’s also an opportunity for them to dispel the myth that young people are lazy and politically indifferent.”

There has been a fall in crime in general in the borough, including gun and knife crime, to which Mr Carryl hopes the school’s campaign has contributed.

But not all schools are so keen to get pupils involved in protest. Schools likely to be affected by the Government’s plans for an eco-town in Warwickshire have been reluctant to join other campaigners. If the Middle Quinton eco-town gets the go-ahead, about 6,000 homes would be built, housing more than 16,000 people.

The plans include one new secondary and three primary schools, but because these are unlikely to be completed until after the new homes are occupied, thousands of pupils could end up being squeezed into existing schools.

According to Izzi Seccombe, a Warwickshire councillor who is also cabinet member for children, young people and families, this constitutes a huge problem for the existing schools in the area.

“The schools will probably have to get extensions built for the short- term, only to have the pupils move to the new schools when they’re built,” she says. Their caution to get involved in any campaign against the building work is “weird”, according to Mrs Seccombe.

But the schools are starting to take the bait. Some of the schools have recently held debates on the issue, one of which demonstrated that those who took part were unanimously against the plans.

It’s not always teachers who spur pupils on to campaign. Some schools are under pressure from parents to take action, in particular when there are mobile phone masts involved.

Glyn Hughes, a parent at Tarleton High School near Preston, said it took him almost a year to convince the headmaster to join his campaign against a nearby phone mast he said was making his daughter and other pupils ill. After four years, the headmaster managed to get the mast moved.

But Mr Hughes has not been as successful in his attempt to get the head of a local nursery to act against a mast that is affecting very young children.

“I think about seven children either at the nursery or living in the area have developed leukaemia - the chance of that being a coincidence is slim, but the nursery won’t get involved,” he says.

Campaign group Mast Sanity says it has been contacted by teachers around the country who are worried about an increase in cancers in their school with phone masts on the roof.

“We find that there are no official investigations of the reported health problems and teachers are too frightened to make an official complaint to the school,” a spokesperson said. “We’re unsure why this is, but in some cases we have heard that governors have links with the phone industry and indeed the Government is pushing this technology, including pushing mobiles for learning into schools despite DCSF warnings.”

I t’s a similar problem for those campaigning against airport expansion. “Many schools are frightened of putting their heads above the parapet, either for fear of being seen to be entering a political arena, worry about upsetting parents who work for the airport, or concern about putting off prospective entrants and new teachers by talking about the impacts of an expanded airport,” says Carol Barbone, director of the campaign group Stop Stansted Expansion. She adds that, in some cases, there are concerns that BAA might withhold the funding it gives to the school.

“We therefore play it carefully with schools. We don’t want to exploit the children in any way. While many young people do get involved, they normally do so through their parents rather than schools,” she says.

There is one way schools can ensure pupils are informed on the issues surrounding campaigns without directly involving them in the activity. Ray Woodcock from Stop Stansted Expansion visits schools in the area to teach them about the plans and what they would mean for the local and wider environments.

“Schools give me anything from 60 minutes to three hours in which I present our case and encourage questions, Mr Woodcock says. “Every school I’ve been to has also invited BAA to make a presentation. The schools try to make this subject balanced and that’s what I try to do.”

Of course, pupils don’t have to be involved at all for a school to campaign. Howe Green House School, near Stansted, chose not to involve the children, aged between two and 11, even though it is strongly against the proposal for a second runway at the airport. The school has instead made representations at the public inquiry into the plans, as it did at an inquiry into plans to allow more planes to use the existing runway. Some would see this as a sensible approach, while others would see it as a missed opportunity to learn.

Back at Hounslow Heath, Ms Harper-Quinn insists that - far from being used as puppets - the children there develop a sense of empowerment through campaigning. “When the BBC came to the school to film, we asked for volunteers and were overwhelmed by the response from the pupils. It’s good for them to think we’re not victims and that we should express our opinions.”

And the children who see presentations by Mr Woodcock take part in exercises that teach them how to listen, ask questions, take notes and report the discussion, he says. “I find it surprising how much children as young as nine are beginning to understand the issues,” he adds.

Not every school will find it easy to attain “citizenship-rich” status and some may not want to. After all, Chris Woodhead, the former chief inspector of schools, referred to citizenship studies as a “distraction” from important topics.

But there’s no denying that teaching the subject and encouraging pupils to be active citizens can bring benefits for the children, the school and the community. As Mr Breslin says, “Although some schools are cautious about encouraging pupils to become active, those that do don’t look back.”

Does Citizenship work?

Even though improvements have been noted at individual schools as a result of introducing citizenship studies, the consensus of the Citizenship Foundation and the National Foundation for Educational Research is that it’s too early in the history of the subject to be able to determine what impact it has had overall.

Tony Breslin, chief executive of the Citizenship Foundation, says: “We’re beginning to see benefits, such as improved results across the board in some schools. We will be able to say more, and say it more confidently, in five years’ time.”

The results of an ongoing longitudinal study by the NFER looking at the long-term and short-term effects on pupils and schools in England should shed some light on the matter after the study ends in 2009-10.

The project is the biggest and longest-running investigation into the impact of citizenship education in the world. Researchers are using a combination of case study visits to schools and surveys with young people, teachers and school leaders. The NFER intends to follow it with a study looking at pupils’ behaviour after they leave school and at university age.

Schools that campaign

• Hellesdon High School, Norwich

• After finding out that about 100,000 marine animals are killed each year by plastic bags, pupils wrote to local shops and asked them to pledge not to hand out plastic bags to customers. Pupils also made environmentally friendly bags, which they sold to raise money.

  • Ysgol Glan Clwyd, Denbighshire

  • The high school was chosen from more than 1,000 other schools in Wales to launch a campaign aimed at tackling gay bullying among young people.

    • Pontymoile Primary, Pontypool

    • Earlier this month Year 5 pupils made a video to campaign to be able to swim at their local pool. They currently have to make a 40-minute bus trip for swimming lessons.