London has lost at least 100 youth centres since the 2011 riots, according to new figures.

The research, compiled from freedom of information (FOI) requests and shared exclusively with Guardian Cities ahead of publication later on Friday, shows the continued decline in youth service provision across the UK capital as austerity continues to grip local councils.

Based on data supplied by 26 of London’s 32 boroughs, the number of youth centres has fallen from 234 since 2011 to 130 this year – a net loss of 104 sites. More than 560 youth workers have lost their jobs in that time.

Siân Berry, the London assembly member and Green party co-leader who submitted the FOI requests, condemned Westminster for effectively forcing councils to make the cuts. “They can’t keep brushing off their responsibility to the young people in our city and expecting squeezed councils to manage on crumbs.”

Youth violence in the city has been rising, with 24 teenagers murdered last year. Research by the Royal London Hospital revealed that children under 16 were most likely to be stabbed in the two hours after school – a time when youth clubs would normally be at their busiest.

The pace of youth service decline in the capital slowed slightly in 2018-19, but overall spending on youth services has now been cut by 46% since 2011, with 29 London councils having cut a combined £26.3m.

“It’s hard to imagine the number of young people these specialist workers and facilities could have been able to support,” Berry said.

Diane Abbott, the shadow home secretary, said: “The Tories are in complete denial about the effects of austerity. Youth services play a crucial role in our communities. If the government are serious about protecting our young people, then they should put their money where their mouth is.”

Projections of youth service spending for 2019-20 suggest more cuts to come, as well as marked disparities between different councils. In the relatively poorer borough of Newham in east London, £603,000 has been added to its youth service budget for the coming financial year, while more affluent Kensington and Chelsea is cutting £1.1m.

Berry’s report, titled London’s Lost Youth Services 2019, does point to one new source of funding: the mayor’s Young Londoner’s Fund (YLF), a three-year project announced in 2018 committing £45m to a range of youth services, including projects placing youth workers in hospital A&E departments, and others replacing some mental health support to young people. The fund is due to last until 2020-21.

Berry repeated calls she made in January to ringfence funding for youth services handed down from Westminster: “The government must fund councils to reinvest in our most valuable asset – our young people – by making youth services a statutory service, and actually funding them from Whitehall.”

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