MPs on the Public Accounts Committee have accused the government of "unacceptable complacency" over soaring levels of homelessness.
A damning new report by the group found there were around 9,000 people sleeping rough in England and 78,000 families stuck in temporary accommodation.
The report said the government's plans to end rough sleeping by 2027 will address only the "tip of the iceberg".
"As we approach Christmas there are thousands of children in temporary accommodation - a salutary reminder of the human cost of policy failure," chair of the committee and Labour MP Meg Hillier said.
"The government must do more to understand and measure the real-world costs and causes of homelessness and put in place the joined-up strategy that is so desperately needed."
Rough sleeping has increased by 134% since the Conservatives came to power in 2010. The number of households in temporary accommodation has increased by two-thirds in the last seven years.
"This report confirms the fact that some government policies are causing homelessness while others are attempting to pick up the pieces," the chief executive of Crisis, Jon Sparkes said.
"Over Christmas and throughout winter, thousands of people across the country will be sleeping out in the cold, and thousands more will be trapped in unsuitable temporary accommodation, or sleeping in cars or on public transport, hidden from help. The mental and emotional impacts of this crisis cannot be overstated: the average age of death of a homeless person is just 47 years old, and they are nine times more likely to commit suicide than the general public. This cannot go on."