It's almost five years since David Cameron set out his ambition to "end the uncertainty, indignity and suffering of rough sleeping" in the government paper 'Vision to end rough sleeping'. This ambition has not been met and the latest statistics provide more evidence that the numbers are moving in the wrong direction entirely.
While I was expecting the latest national rough sleeping statistics to show a further rise in the number of people sleeping out on any one night, I was shocked to see the number jump 30 per cent in one year.
I know from speaking to colleagues who work day in, day out with people sleeping rough that they will persist for as long as it takes to help people move off the street by connecting them to accommodation and services. But they also tell me they are increasingly concerned about the challenges faced by their clients with mental health problems.
Our new report Stop the Scandal: 'an investigation into mental health and rough sleeping' brings new evidence to the table on the extent of the problem. Analysis of the data available to us revealed four in ten rough sleepers have a mental health problem, rising to over half of rough sleepers from the UK. In a survey of 225 street outreach workers from across the country, 62% said the number of people with a mental health problem sleeping rough was increasing in the area that they work in.
I've heard from people with first-hand experience and seen hard evidence of the many factors driving the rise in rough sleeping. Factors including high housing costs and benefit cuts, a shortage of supported housing and hostel places and an increase in destitution among people from central and eastern European countries.
I would like more politicians to see for themselves how certain decisions are driving the rise in rough sleeping and the terrible impact it has on individual lives.
I would like them to read our research which also found that cuts to specialist mental health services are leaving people stuck sleeping rough for longer because they can't get the support they need to move off the street, even though we know sleeping rough can make someone's mental health so much worse.
In a speech on life chances last month, the Prime Minister recognised that too many people are held back because of poor mental health. He was right. He also said "the economy can't be secure if we spend billions of pounds on picking up the pieces of social failure and our society can't be strong and cohesive as long as there are millions of people who feel locked out of it."
If David Cameron joined St Mungo's on an outreach shift I know this is exactly what he would see - people stuck sleeping rough who feel totally shut out of society, desperate for the chance to transform their lives.
This is why I am convinced the Prime Minister must to renew his ambition to end rough sleeping and stop the scandal of people with mental health problems stuck on our streets.
The new government statistics show rough sleeping in England has more than doubled since 2010. In London, the number of people recorded sleeping rough with a mental health need has more than tripled over the last five years from 711 in 2009/10 to 2,342 in 2014/15.
It's time for David Cameron to lead a new, ambitious rough sleeping strategy which ensures that government departments and the NHS work together. The strategy should deliver mental health assessments and professional support to people on the street, specialist supported housing to aid recovery and the right support upon discharge so people don't end up sleeping rough after leaving mental health hospitals.
The government should also improve to homelessness legislation to prevent more rough sleeping, and alongside our colleagues in the homelessness sector we are calling for a new, universal prevention and relief duty on local authorities to ensure that anyone threatened with homelessness can access help.
Rough sleeping is dangerous and ruins lives. People with mental health problems are particularly at risk. The government can, and must do more to help.
I hope thousands, maybe more(!), will help us press for change by backing the Stop the Scandal campaign and signing our open letter to David Cameron at www.mungos.org/stopthescandal
Beatrice Orchard, Policy, Public Affairs and Research Manager, St Mungo's