It’s a freezing January night, the wind whipping against the trimmed hedges and double-glazed windows of the seafront semis by Shoreham Harbour. Rachel Beckett, 18-years-old, can’t accept a cup of coffee from a Thermos, because it has milk in it. She hops up and down in her vegetarian Doc Marten’s (made without leather) and says, only half-joking, that her beliefs keep her warm.

The storms at sea are such that the scheduled shipment of calves has been cancelled; around 100 protesters have turned out, their numbers dwindling fast as the wind and the word get round. Rachel’s friend Naomi Stewart, also 18, is disappointed at the low turn-out. “Sunday’s always a quiet night,” she keeps saying. Three days later, Shoreham Port Authority announces its decision not to renew the contract for exporting live animals from the small Sussex harbour, to the jubilation of Rachel, Naomi and animal-lovers around the country.

Many of those involved in the animal welfare demonstrations at Shoreham and Brightlingsea have been young people, reflecting the level of interest of children and teenagers in animal rights. Surveys consistently show at least 10 per cent of secondary school pupils describing themselves as vegetarian, and many have strong views on a broad range of animal welfare issues, ranging from factory farming and animal testing to hunting, the fur trade and endangered species. But how deeply held are these convictions, and what outlet do pupils have for their beliefs?

Compassion in World Farming (CWF) is just one of a growing number of animal welfare groups currently riding high on the publicity generated by protests against live export. While many people may be on a steep learning curve regarding veal calves and pig farrowing crates, many schoolchildren are already familiar with the issues. “We know from our work in schools,” says CWF’s education director John Callaghan, “that this has been a burning issue with young people for a long time. Kids have a natural sense of justice and fair play, and are very concerned both about their fellow human beings and animals. ” Out of a membership of 12 to 14,000, Compassion in World Farming has 4, 000 members under the age of 18.

According to Steve Connor, campaigns director at the Vegetarian Society, some children develop their first vegetarian leanings as early as three or four. “The first books they’re given are about fluffy farmyard animals, hens in copious amounts of hay, pigs frolicking around in the mud,” he says. “And their first toys are big-eyed, dewy, stuffed animals. All of their instinctive reactions are geared towards compassion for animals. And then there’s this huge shock when they discover that they’re actually being slaughtered for their food.”

While a minority of children grow up in vegetarian homes (about 5 per cent of adults in this country are vegetarian), the four-year-old refuser is more likely to be persuaded by parents to continue to eat meat, and not dwell on where it comes from. Steve Connor describes this as “parents succeeding in bringing the veil of cynicism down”. But there is a strong resurgence of interest in vegetarianism and animal welfare in early adolescence, particularly amongst girls.

“I don’t think that it’s something that suddenly dawns on teenagers,” says Steve Connor, “because most teenagers are aware of what meat is. But it’s at that point that they’re first starting to flex their ethical muscles. They’re making their first adult decisions, and their first moral decisions.” The greater interest amongst girls is generally ascribed to their tendency to mature earlier, as well as to be more focused on issues such as diet and the ethics of animal testing for cosmetics.

John Callaghan dares to say that they are more sensitive. “Girls usually take the leading role, and boys come on board. Maybe it’s not quite as acceptable in the peer group for boys to come out as a vegetarian, or someone who’s concerned.”

Rachel Beckett was 12 when she first stopped eating meat and is now a vegan, which means she will not eat animal products. She has taken a leading role for some time. “It was the cruelty to animals,” she says, “not only factory farming but the transport, the way they’re slaughtered. Then I started campaigning and learned about a lot more reasons to be vegetarian.” Rachel became a youth contact for both Compassion in World Farming and Animal Aid. She set up a “young vegetarian group”, drawing members from six schools, and gave a talk in her own school on BSE (bovine spongiform encephalopathy) or “mad cows’ disease”.

Initially the only vegetarian in her school year, Rachel says her commitment isolated her. “I used to ring the Vegetarian Society in the lunch break, just to talk to other veggies. People do hassle you, taking the mick out of soya all the time.” The posters she put up in school of animals in distress did not go down well with the deputy head. “I had to choose posters with pulses on them.”

Currently taking a year off before going to study law and French law at University College, London, Rachel has grown more rather than less committed, and intends to work in animal rights after she graduates.

Naomi Stewart also paid a price at school for her convictions. At her first secondary, Bedales, an independent boarding school in Hampshire, “everybody was really into vegetarianism”. But at the Sussex comprehensive where she did A-levels, interest in animal rights was minimal and dissection part of the biology syllabus. Naomi partly blames her refusal to cut up a mouse - in an assessed practical - for the fact that she failed her biology A-level.

But her anti-dissection views caused problems all through the course, she says. “My biology teacher thought I was just squeamish and girly. It caused a lot of friction between him and me. then when I was having real problems with my biology I couldn’t talk to him about it.”

None of the examining boards now insists on dissection for biology A-level, nor does the national curriculum, although some teachers still make it compulsory. Animal Aid, which campaigns mainly against animal experiments and factory farming, presented a petition calling for a total ban on dissection in schools to the Department for Education last autumn, signed by 25,000 pupils.

The main thrust of their argument, says Mark White, youth group co-ordinator for Animal Aid and a former teacher, is that “dissection is bad education. It’s teaching children that animals are just laboratory tools, to be used and then discarded.”

Teachers make widespread use of the educational resources offered by animal welfare groups. Issues such as factory farming and animal testing are close to home for students, and pose complex moral questions which can stimulate good debate. Still, animal welfare bodies have been accused by interested parties, such as the Meat and Livestock Commission, of spreading propaganda in schools. CWF, whose pragmatic mission is to promote the welfare of farm animals during their rearing, transport and slaughter, denies this. “We encourage people to discuss the plight of farm animals,” says John Callaghan. “We don’t tell pupils what to think.” Similarly, Mark White of Animal Aid says: “We go to put a particular point of view. We expect to generate a discussion, not to go in and convert people.”

But Steve Connor is an unabashed proselytiser. He bases his talks in schools on his own conversion to vegetarianism at the age of 16, and laces it with soundbites such as: “I suddenly realised I was calling one set of animals ‘pets’ and the other ‘dinner’”, and “if you care about animals you can’t really have one on the end of your fork”. His highest conversion score (based on children putting up their hands at the end of the talk if they intended to become vegetarian) was nine out of 20.

He defends his pro-active stance in schools by saying that the meat industry is targeting children so heavily “that we have to do something. It makes me want to weep when I go into classes and they’re talking non-stop about burgers.

“Then the real killer is when the kids go home and say ‘I want to go veggie’ - and their parents say no.”

Ironically, while many adults abandon red meat for health reasons, parents often worry about the health aspect. One father in Glasgow, with a 14-year-old vegetarian daughter, is concerned that she “just takes waffles and crisps. And broccoli sometimes. She’s very tall and at times you look at her and think she’s anaemic.”

Certainly, a junk food diet which excludes meat does not become a healthy one. Fourteen-year-old Kirsty Wilkes says that when she first became vegetarian at 12 she lived on pizzas and tinned food, and became overweight. Now, she eats a lot of fruit and vegetables, a wide range of pulses, and rice and pasta. “I’ve lost weight and have a lot more energy.”

Other parents perceive their child’s nascent vegetarianism as an attack on their own values and family life. One of the potent lures of animal activism for teenagers is that it is a legitimate form of rebellion, potentially against everything from mum and dad to agri-business.

Lisa Miller, consultant child psychotherapist at the Tavistock Clinic, London, believes there is more to teenage activism than concern for animals, however sincerely held.

“The love of a cause is very pronounced in adolescents,” she says “because it seems to offer a way out of all the really besetting conflicts that greet the emerging adult. It simplifies, it gives you a group to fight with and, very important, a group to fight against.”

Philip, 23, is an organiser for the Hunt Saboteurs Association (HSA), in a southern county of England. He first got involved in direct action against hunting in his own village at the age of 17, and now extends his activities to demonstrating against the Criminal Justice Act (which, among other things, makes trespass on private property a criminal rather than a civil offence). He has been arrested six times by the police, and charged once (with causing criminal damage to a hunstwoman’s video camera). He concedes that this is starting to worry him. “The first time you get nicked it’s not very nice, ” he says. “But by about the third or fourth time you start to get a bit casual about it.”

At this sharper end of the animal welfare spectrum, young people can be at serious physical risk. Tom Worby, a 15-year-old from Cambridgeshire, was killed by a hound van on his first hunt saboteur outing in April 1993. Two years previously, 18-year-old saboteur Mike Hill was killed. Since the deaths, the HSA has recommended to local groups that they should not have any participants under 17, except with their parents’ presence or express permission.

The HSA, says Philip, none the less gets many calls from interested teenagers wanting to take part, some of them as young as 13. “We have to say ‘sorry, it’s best to leave sabbing for a couple of years’,” he says. “But there are other things they can get involved in, like leafleting or raising money.”

Animal rights’ campaigners are often criticised for being more exercised over animals than people. But activism, which may begin in a young child’s feeling for lambs or calves, can spread in the older teenager to wide-ranging concerns covering a broad political sphere. “Vegetarianism does not exclude,” says Steve Connor of the Vegetarian Society. “It augments. It sits very comfortably alongside anti-racist movements, peace movements and particularly environmentalism, which is such a call to action for the young today.”

Animal Aid, The Old Chapel, Bradford Street, Tonbridge Kent TN9 1AW The Vegetarian Society, Parkdale, Dunham Road, Altrincham, Cheshire WA14 4QG Compassion in World Farming, 5A Charles Street, Petersfield, Hants GU32 3EH The Meat and Livestock Commission, POBox 44, Winterhill House, Snowdon Drive, Milton Keynes MK6 1AX