Research by the charity Crisis shows that up to a quarter of Britain's homeless have served in the armed forces. The charity says that many ex-servicemen end up there because they have left a job which provided them with a home and a lifestyle, or because years of institutionalised life have left then unable to cope with the outside world.
Last week, recruitment officers from the Parachute Regiment's Queen Elizabeth barracks near York picked up 22 homeless young people in Leeds and took them for a promotional day out.
The Army is only interested in the young and healthy. Capt Paul Larkman, who conducted the operation, said: "We are after people who, through no fault of their own, find themselves on the streets."
Among those bedding down in doorways in central London last week, the proportion of ex-soldiers was high. Many were reluctant to consider signing up again or recommending a military career to younger friends.
Andy Howarth, 31, was once a Lance Corporal in the Royal Engineers. He now sleeps in and around The Strand and numbs himself from the cold by drinking at least six bottles of Thunderbird a day. "I got a medical discharge from the Army because they said I was a little bit nutty. I had a psychiatrist. I had two tours in Northern Ireland and saw people die," he said.
The charity Shelter has tentatively welcomed the Army's interest, but a spokeswoman said the recruitment plan needs to be backed up by on-going support for those recruited and for those who may eventually leave.
"Obviously, there will always be a high proportion of ex-servicemen on the street because they are leaving a job which provided them with both a home and a lifestyle," she said. "Many will never have had to cope with normal things like paying bills."
Care agencies believe under-privileged and emotionally disturbed people are often drawn to the security of the armed services and are the people least able to cope when they leave.
But the Army is sceptical about statistics showing the high number of ex-soldiers on the street. "If you find a former serviceman on the street it will be noted, whereas you don't hear so much about ex-accountants on the streets," said a spokesman.
"It is also true that sometimes these people who say they are former servicemen were in the Army 15 years ago." Resettlement provision for those who leave has vastly increased in recent years, he said.