The number of rough sleepers on London’s streets has more than doubled in five years because of a “toxic mix” of cuts, government failure and a lack of support for people arriving from EU countries, according to figures from a network of charities.

Statistics show that the number of people sleeping on the capital’s streets has risen to more than 7,500 in 2015, up from 3,673 in 2009-10.

The number of rough sleepers across England as a whole has also risen, though the problem is more acute in London. Statistics released by the Department for Communities and Local Government(DCLG) earlier this year show that across the UK 2,744 people slept rough on any one night in 2014 - up 14% on the previous 12 months.

Homeless charity Crisis said the rise was caused by cuts to benefits, a chronic housing shortage and the “longstanding legal injustice” where many homeless people are not considered a priority for help.

Charities said the trend was deeply concerning, and called for action at the national and EU level.

“Worryingly … the number of people who’ve previously slept rough and are returning to the streets is rising,” said Howard Sinclair, the chief executive of the homelessness charity St Mungo’s Broadway. “We need to ask what more can be done for these people, what gaps need to be filled to prevent repeat homelessness.”

London’s housing crisis has deepened in recent years as rising rents and a fall in social housing have left many families struggling to find somewhere to live. Sadiq Khan, Labour’s London mayoral candidate, who spent a shift working with St Mungo’s before Christmas, said the rise in rough sleeping was the most stark example of a system that was failing millions of people in the capital.

“The rise in homelessness has been caused by a toxic mix of government failures: allowing London’s housing crisis to go from bad to worse with fewer genuinely affordable properties available every year, cuts to social care and local authority funding which means there is less support for people who are at immediate risk of becoming homeless, and direct cuts to grants and programmes for organisations that tackle homelessness. Taken together it’s had a devastating effect.”

Khan, who is standing against the Tory Zac Goldsmith to succeed Boris Johnson, said:“Homelessness is becoming an increasingly visible scar on London’s streets once again just as it did the under the Tories in the 1980s.

“Labour tackled the problem of rough sleeping in London then, and we’ll do it again now. We have a moral responsibility to tackle rough sleeping and not to turn a blind eye. That must mean tackling the root causes of the problem.”

The latest figures were gathered by the Combined Homelessness Information Network (Chain), which is commissioned and funded by the mayor of London’s office and managed by St Mungo’s.

The charity said the causes of the rise in rough sleeping, which had to be addressed, included:

• Cuts in council funding that mean many authorities struggle to find housing even for those in the most dire need

• The growing number of people coming from the EU to find work who end up sleeping rough after being exploited by employers

• Housing benefit cuts and an insufficient supply of genuinely affordable housing

• Cuts to mental health services that leave many vulnerable people with nowhere else to go

A homeless person sleeps on a bench on a London street.

Photograph: Jonathan Brady/PA

Sinclair said many types of people found themselves on the streets. “It is clear that new groups of people are ending up on our capital’s streets who have very different stories and reasons for being there, with migration being a significant driver in these most recent figures.

“We should be careful, however, not to jump to conclusions on short-term trends, but we do know that traditional routes off the streets are often not available or appropriate for these groups, and we believe that people living on the streets following migration is an issue which requires a joined-up policy approach from the UK government and the European Union as much as from local government.”

A statement from the mayor of London’s office said any person sleeping rough in the city was a cause for concern and something Johnson took extremely seriously.

“He invests £9m a year in vital services that help rough sleepers off the streets, including specialist services for non-UK nationals sleeping rough, a group that has significantly increased in recent years,” the statement said. “Through the success of his flagship No Second Night Out scheme, the majority of those who arrive on the streets spend only one night sleeping rough.”

It said the mayor had recently secured £30m for hostel accommodation, including specialist housing for younger people at risk of sleeping rough. “The mayor remains committed to working with government, local authorities and the voluntary sector to help ensure no one has to sleep rough on the capital’s streets.”

A volunteer seamstress repairs clothing at a 2015 Christmas homeless shelter in north London. Photograph: Felix Clay/the Guardian

On the streets

A man in his 40s jumps up from his tatty red sleeping bag on the floor of a London tube station following a brief exchange with two St Mungo’s workers.

“Romanian, I give work,” he says to Adam McFarlane and Laila Grinberga, hurrying over to rummage through his belongings in a makeshift camp lit by the station’s unforgiving fluorescent light. Another man, a Pole, beds down under an array of plastic bags hanging up on the walls. A takeaway container next to the sleeping bag holds a few copper and silver coins.

The Romanian, who is known to the outreach workers, returns waving papers, which he hands to them.

His boss, from a bakery in Cambridgeshire, has taken away his passport, he tells them. Grinberga suspects he is a trafficking victim. “There are markers of trafficking and keeping someone’s passport is one of them” she says. “We’ve noticed a three to four-week shift pattern in bakers where people are not getting paid. These people are very vulnerable.”

Rough sleeping in London has increased 16% in the last year alone, according to Chain. Almost half of those doing so in 2014/15 were European, with 36% from central and eastern Europe and 10% from other EU countries. The proportion of British nationals among the capital’s homeless population has fallen over the past two years from 47% to 43%.

Petra Salva, the director of homelessness and outreach at St Mungo’s, now visits agencies in Romania and Poland to work on collaborative projects that make it easier to help those on the streets return home.

Before leaving their office at the Barbican, Grinberga and McFarlane had checked a whiteboard of names of recent referrals to the team, so that they could check their progress on their patrol. On the streets, however, people can disappear or refuse the help they signed up for. They had previously offered the Romanian man at the tube station an assessment, a translator and temporary shelter, but he abandoned the facility and is back on the street. The suspect he has alcohol problems.

Many eastern Europeans they see are economic migrants, who come to Britain to work, but are unskilled or ill-prepared. Others are vulnerable individuals or victims of what Salva describes as “soft trafficking”, in which people have been coerced or misled into coming to Britain by the promise of employment. A third group, who come to the UK temporarily to send money back home, see living on the streets as a way of cutting costs.

“The problem is, the longer they stay on the streets, the more problems they will have” she said. “That is not OK.”

Karen McVeigh