MAI TRUONG never walks around the North Peckham estate in south London where she lives: in the mornings she hurries out of the front door of her three-storey council maisonette, down a narrow concrete stairwell - where muggers sometimes lurk - and into the family car parked below.

A slight, elegant woman, she drives her husband, Huan Cong Dang, to the Victorian school which houses the Southwark Vietnamese Refugee Association centre where he works, before going on to Goldsmiths' College, where she is studying for a diploma in youth and community work.

Mai and Huan moved to the estate 12 years ago, when it was home to the largest concentration of Vietnamese refugees in Europe. Today, numbers have dropped from more than 2,000 to under 400. But three-quarters of Britain's 24,000-strong Vietnamese community still live on inner London council estates. Their needs, according to a recent report by the Community Development Foundation, are largely ignored by the councils and other social agencies, and their lives are dominated by fear of attack and racist abuse.

North Peckham estate is a grim expanse of 50 concrete blocks comprising 1,449 flats and connected by 16 miles of concrete walkways, although these are now being demolished and money is being spent to improve the housing and surroundings. Like Mai, most of the Vietnamese residents are frightened to go out alone.

Mai, 37, and Huan, 38, a reserved but purposeful man - he is working on a PhD in maths and computing at the University of North London - were teachers in South Vietnam before the tightening screws of Communism forced them to flee, with thousands of others, as 'boat people' in 1979. Mai apologises for the untidiness of their home: 'We're both so busy working and studying, there's no time for housework.' They also run English and mother-tongue classes and provide support for the 65 per cent of their community who are unemployed.

They speak passionately of the value of education, and they have great hopes for their two children. Vu, 14, who is at Haberdashers Aske's school in New Cross, was born in Tra Vinh, their home town south of Saigon, just before they escaped. He hopes to go to Oxford and become a doctor. Their daughter Vi, 12, was born in Britain. Both are bilingual, but prefer to speak English.

Over supper - stir-fried chicken and beef - Mai, Huan and a friend, Tuan Dui, a 28- year-old man who has just 'broken through the wall' into a mainstream job with Greenwich council, quizzed me on my politics. 'We can't vote, we don't have British passports - but we did like Mrs Thatcher.'

Looking out of the window at the scruffy flats opposite and scrawny grass below, Mai sighs. 'At home on warm evenings like this we used to cycle out to the countryside - it was very beautiful, flat but pretty. It was wonderful to sit in the shade of a big, old tree on a hot day.'

Like other Vietnamese, Mai and Huan want to leave the North Peckham estate - they hope to be able to buy somewhere in Dulwich within a few years. Council officials say surveys show that tenants in general think life is improving on the estate; but the Vietnamese continue to be the most negative group. They put this down to language difficulties, and now provide Vietnamese- and Chinese-speaking interpreters in the housing office.

Life for the Vietnamese immigrants has moved on from the confusing days in the Seventies when they first arrived. Now many of the younger generation are gaining university degrees, getting decent jobs and finding their feet. Others have set up restaurants, shops, clothing factories: one man, a former tank commander, turned to making cooking ranges for Chinese restaurants.

The last sizeable group of Vietnamese refugees came to Britain three years ago, when the country opened its doors to 2,000 mostly poor, barely literate farmers and fishermen who had been held in camps in Hong Kong. They are among those most isolated by language and unemployment.

The next day, Huan is standing on a fire escape outside his office overlooking the leafy gardens of the Victorian back-to-backs. Staring into the distance, far beyond the houses towards the wooded brow of a hill, he talks of home: Tra Vinh, a city of 40,000 people, where he taught science at secondary school and lived in a large old family house. He feels responsible for doing well here; it was he who organised the escape boat for 38 people (which cost 70 ounces of gold); he who moved the family to London from Margate to improve their chances; he who studied and worked to make something of life here. But still not a day goes by without homesickness, remembering those he left behind: his parents, family and friends.

'The poorer refugees, those who were farmers, fishermen, or worked in factories and can't speak English, they are quite happy to stay here: they're better off, have nothing to go home to. But every day I look forward to the day when the Communists have gone and we can go home.'

Abruptly he changes the subject and the moment passes, but the message is clear: Huan is a refugee, not an immigrant.

In fact, poorer, less well-educated people have fewer options than Huan: many have still not learnt English and live on benefits, trapped in poverty. Huan displays rare flashes of anger when this subject comes up: refugees have a duty to learn the language and become fully functioning members of British society, he says; they owe it to themselves and to this country for accepting them. But he is also angry at what he sees as half-hearted government efforts to ensure that refugees learn English. He believes those who cannot speak English should be compelled to attend classes as a condition of their benefit.

In the large schoolroom in the SVRA centre where Mai gives her English lessons, An Nguyen, 40, a single mother and factory worker who fled Hanoi in 1980, says, with Mai interpreting: 'I left Vietnam because I wanted to live in a free country. The biggest difficulty I have found here is the language and I am frightened to go out in case my house is burgled or I am mugged.' Next to Mai, a depressed-looking woman with a wide, peasant face glowers at me: 'Will this take long? I don't want to leave my house unattended,' she says, in Vietnamese.

The next day, when Huan's son Vu is giving me a walking tour of the estate and its neighbours, I glimpse her sitting in the waiting room of the health centre, wearing the same fixed mask: a combination of depression, anger, fear and disappointment.

The biggest single cause of ill health in the community is depression. At Tooting Bec Hospital, south London, the Vietnamese Mental Health Project provides six beds in a hostel staffed with Vietnamese doctors.

Vu, a bright, polite boy, looks anxious as we turn corners or scuttle down stairs: here, by some empty, shuttered shops, is where his mountain bike was stolen; over there - he points - is one of the 'mugging spots'. Some of the young Vietnamese have formed gangs - to look after their own, but also to commit crime, Vu says. He knows a few of them by sight only, and reckons there are 60 members aged 13 to 17. They tend not to hang out on the estate, preferring amusement arcades.

The adults seemed ignorant of the gangs' activities but the Vietnamese community can present a solid front to the outside world. On the occasions when police have investigated incidents involving teenagers they have been met by blank silence.

Life for the Vietnamese in Britain is hard and their world is rarely revealed to outsiders. But their lack of self-pity and poignant sense of sadness and separation from the country of their birth is apparent to all.

One night over the dinner table, when I asked Huan where he came from, he unfolded a map of Vietnam and pointed out his home town, the place he and Mai escaped from, and the spot a British ship rescued them as 12 Thai pirate junks closed in.

Then he produced a hand-written note the ship's captain had written when the refugees were dropped off in Singapore. It reads: 'Dear People, We on board this vessel - motor vessel 'No Name', from 'Nowhere' - wish you the best of luck and safe landing. We are a free-speaking nation and we believe in freedom. Good Luck and God Bless, from all of us. The Boss, No Name.'

Anonymous as the note was meant to be, Huan Cong Dang knows the captain's name, and the ship's name: the Ashford Jersey, from Southampton. Although he spoke no English then, he had enough sense to pick up a piece of headed paper and quietly tuck it away: a talisman for his new life as a refugee.

(Photographs omitted)