Nearly half of British armed forces veterans live on disposable incomes of less than £10,000 a year, a Royal British Legion report suggests.
The report was released on the eve of Armistice Day
The survey of 1,200 ex-service people and their dependents found that half had a long-term illness, disability or infirmity, and 55% had welfare needs.
The charity's Director of Welfare, Sue Freeth, said £10,000 was simply not enough money to live on.
The report was published as the Queen honoured war dead in central London.
She planted a tiny wooden cross on the Field of Remembrance, symbolising one of the many fallen heroes of the world wars.
Meanwhile hundreds of veterans gathered in the grounds of Westminster Abbey to see row upon row of crosses - each bearing the name of a lost loved one.
The Royal British Legion report, released the day before Armistice Day, estimates that 10.5 million people make up Britain's ex-service community.
The average net household income was £15,500 yearly, it said.
Some 46% said they had net household income of less than £10,000 a year - the amount the government says is necessary to live on.
One in 10 - or 11% - said they had net household incomes of £5,000 a year.
But the report issued a note of caution on these figures, saying that no detailed financial analysis had been requested.
It was also not clear whether some people had counted their state benefits as part of their household income or not.
Although the vast majority (91%) reported they were happy, those on incomes of less than £10,000 per annum tended to be the worst off.
Eight out of 10 of these were in the bottom socio-economic group, E, and 78% of them were dependent widows or widowers.
Ms Freeth said she was surprised at the numbers of people living on incomes below £10,000.
"This really is not adequate," she said, adding that it reflected the sorts of requests being made for basic goods to the Legion's welfare department.
"When people have to replace essential household items like washing machines they often end up doing the washing themselves."
She pointed out that ex-service personnel who had been in the armed forces before the mid-1970s had a lower level of war pension than those who had served after this date.
She added: "People who served their country when they were asked to should be entitled to a more comfortable life in their old age."
The Commons is due to observe a two minutes' silence on Friday in remembrance of those who gave their lives for the country.