Homelessness in England has become more entrenched over the last four decades, says housing charity Shelter.
Things have got worse since Cathy Come Home, says charity
Since 1976 the number of families in temporary housing has risen from 6,400 to more than 100,000, a report to mark Shelter's 40th anniversary says.
It blames the rise on a "historic low" in the building of social housing.
Housing minister Yvette Cooper said significant progress tackling homelessness had been made but the government "had to go further".
"The next challenge is to get families out of temporary accommodation. We have to recognise that this country has built too few homes for a generation.
"We need to build more social housing, more private housing and more shared ownership to meet families' needs," Ms Cooper said
But the government had already ended bad housing for hundreds of thousands of children, thanks to a major programme of refurbishment to council housing since 1997 and stopping the use of bed and breakfast accommodation, she added.
Shelter was set up in 1966 after BBC film Cathy Come Home, about how an average family ended up homeless, sparked widespread public concern about the scale of the problem.
Cathy Come Home
Broadcast in December 1966
One of TV's first 'docu-dramas'
Widely cited as 'defining' moment in 1960s television
Showed how TV could influence political agenda
Written by Jeremy Sandford, directed by Ken Loach
Starred Carole White and Ray Brooks
Shelter's director Adam Sampson said in practical terms little had changed since the film was broadcast.
"With more than one million children in bad housing it is a national scandal that even more families are suffering the kind of long-term damage and insecurity witnessed in that heartbreaking film about homelessness," he said.
The government has announced plans to build an extra 10,000 social homes a year by 2008 and set a target of halving the number of families in temporary accommodation by 2010. It has also promised to make social housing a priority in the next spending review.
But Shelter is calling for a commitment to end bad housing for children similar to the government's pledge a decade ago to reduce the number of rough sleepers on Britain's streets.
Government figures published last June suggested the overall number of homeless people had fallen by a fifth year-on-year.
However, Shelter said the figures should be taken with a "health warning" because many council staff felt pressured to reduce the numbers of people they accepted as homeless, an assertion denied by the government.