Although military authorities insist that the problem is small, and only affecting young men with unusually large families, soldiers' wives and welfare organisations say that many more service personnel are struggling to make ends meet - but are too proud to seek the help which they need. Tony Bradshaw, a 19-year-old lance-corporal at Quantico, a US Marine base 30 miles south of Washington, who has been receiving food stamps - vouchers that can be exchanged for goods at shops - for the past two months, said: "It's very hard to realise and admit it. I have to do whatever I can to provide for my family. But I did not expect it to be like this when I joined up."

A family of three - with one child and the wife not working - would qualify for food stamps if their pre-tax income is less then $873 (£528) per month. A two-child family would qualify on income less than $1,176 (£705) per month, rising to $2086 (pounds 1252) for a family with five children. Food stamps worth $142 (£85) a month have helped eke out the $1,000 (£600) monthly pay cheque on which L/Cpl Bradshaw, his wife Tenille and their two young children must live in a small, tin house in the middle of the base. Mrs Bradshaw said: "Without food stamps my children would not be having much of a Christmas." But the system can be humiliating. Despite having no other means of paying, L/Cpl Bradshaw was not allowed to buy a loaf of bread at the base's military supermarket recently because although he had his food stamps, he did not have with him an official card stating he was entitled to them. A long line of other shoppers, many of them fellow marines, saw him being refused.

Denis McFeely, food stamps programme manager at the nearest social services office to the base, said: "The coupons identify an individual in a check-out queue as being on a low income. Other people look to see what is being bought with their tax dollars. The programme has a stigma attached to it." That is one reason why the true number of US servicemen and their families entitled to receive food stamps is almost certainly far higher than the 12,000 who actually do so. The problem for young recruits to the American forces is that many in the junior enlisted ranks earn only just over $1,000 a month before tax. Even after allowing for free - if rudimentary - housing and other benefits, a package that may be adequate for single soldiers puts those with even small families well below the official American poverty line.

Military pay has fallen behind the rest of the American economy as a result of budget squeezes over the last decade, and a recent vote by Congress to grant a 4.8 per cent increase from January still leaves a wide gap. Senator John McCain, who is trying to beat George W Bush for the Republican presidential nomination, is repeatedly raising the subject in his election campaign. He said: "These enlisted service members proudly wear their uniforms on our behalf, ready to make the ultimate sacrifice. They are the very same Americans sent into harm's way in recent years in Somalia, Bosnia, Haiti, Kosovo and now East Timor. They have a right to a decent salary." It is a sentiment shared by many at Quantico, where 7,200 marines, many of them officers in training, live and work inside the sprawling, 10 square-mile base with a small civilian town at its centre. Although the base boasts a marina and a leafy golf course, frequented by the marines' upper echelons, living conditions for lower ranks are more down-to-earth.

In one recent case a young soldier, his wife and their baby lived without furniture in their newly-allotted house for three weeks before contacting a voluntary group in desperation. Tobias Miller, 18, who arrived at the base in March from Missouri with her husband Mike, a lance-corporal, shortly after he completed his basic training, said: "We slept on the floor for three weeks before I got up the guts to call someone." Almost all the furniture in their two-bedroom home was subsequently given to them by an organisation called Help - Help Enlisted Lives Prosper. Mrs Miller and her husband also reluctantly decided to apply for food stamps. But after three separate visits to a social services office outside the base, during the last of which they were forced to wait for three hours, they gave up because they could not endure the humiliation.

Mrs Miller said: "My mother was on food stamps and I never wanted to be on them myself. This isn't what my husband's recruiter led us to expect." Lisa Joles, 35, the energetic founder of Help and the wife of a local marine, has become an unofficial welfare officer for many of the young families who arrive on the base, often to set up home for the first time. She encourages them to apply for food stamps and other welfare benefits. She has also worked hard to publicise the problem, something which has not endeared her to the marines' authorities. They have their own support system which Mrs Joles insists she is trying to complement. They point out that any problems are not unique to Quantico.

Most weekends Mrs Joles and her husband, Baron, an infantryman, distribute large quantities of furniture, clothing and other household goods which have been donated either by better-off marines or by sympathisers. Families like the Bradshaws and the Millers have equipped most of their homes that way. Last week L/Cpl Eric Clay and his family - wife Alisha and children Kelsey, aged three and one-year-old Emily - were praising Mrs Joles as they sifted through the mound of material she had gathered in a shed behind her house. Mrs Joles also organises small squads of wives to do temporary work for local employers, helping boost their families' income. But she is no soft touch: if the women do not learn how to manage the extra money they earn she will not ask them back. She said: "I don't want them coming back two weeks later saying they don't have enough money to buy diapers.