Support services for single homeless people in England have lost £5bn since 2009, leaving people at risk with "nowhere to turn", charities say.
Analysis for St Mungo's and Homeless Link found as councils faced central government funding cuts, such services lost an average of £590m a year.
Rough sleeping, the most extreme form of homelessness, rose 165% over around the same period, the charities say.
The government has set up more projects to tackle the issue since 2018.
The charities acknowledge that the government has announced additional funding for local authorities for the coming years.
But this is dwarfed by the money that has been lost over time, they said.
The charities commissioned researchers who looked at official spending data for all of England's local authorities.
They cross-referred it with information on how many single person households and families were classed as homeless in different local authority areas.
This enabled the team to arrive at a more accurate estimate of funds lost to services for homeless individuals.
It found that if total expenditure on homelessness-related services had stayed constant from 2008-9, more than £5bn extra would have been spent.
It also found that in 2017-18 local authorities spent £750m less on homelessness-related activity than they did in 2008-9, despite the rise in homelessness.
Councils and service providers told the researchers of a worrying reduction in the services aimed at preventing homelessness - such as family mediation and tenancy support.
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Howard Sinclair, chief executive of St Mungo's, said: "The human cost of these cuts is all too real.
"The people we work with - many struggling with poor mental health, substance use or domestic violence - are often being left with no option but to sleep rough.
"With nearly 600 people dying on our streets or while homeless in a year, this really is a matter of life and death."
He urged the government to put the money back and to turn the tide of rising homelessness.
Rick Henderson, chief executive of Homeless Link, a charity which represents those working in homelessness and housing sector, said: "There are too many people sleeping rough and facing homelessness in this country - we can see it every day on our streets and it is unacceptable.
"Local authorities have a key role in supporting people who are homeless, or at risk of homelessness, but they can only do so if they have enough money to fund services properly."
Minister for Housing and Homelessness Heather Wheeler said: "No-one should ever be without a home and the Government is committed to preventing and reducing all forms of homelessness, backed by £1.2bn of funding so far.
"We have also implemented the Homelessness Reduction Act, which helps more people get the support they need, and at an earlier stage.
"The £100m-backed Rough Sleeping Strategy was launched last year and sets out the government's blueprint for ending rough sleeping for good - including access to specialist support services and housing advice."