It also says nearly a fifth of us know someone facing some form of homelessness this Christmas – either sleeping on the streets, in their cars or on a friend’s sofa.
St Mungo’s have a number of services across London, including in Clapham.
Matthew Bawden from St Mungo’s says a “chronic shortage” of housing is a key factor.
The government says it’s committing 2-billion pounds to tackle the issue.