The union, which is holding a conference today in Eastbourne for its Community, Youth and Playworkers' section, said local authorities in the UK have made £123m worth of cuts to youth services over the past two financial years, resulting in the closure of 244 youth centres on top of 359 that were closed in the previous two years.
It is calling for the chancellor to set money aside to support the sector. It also wants youth services to be made statutory, funding to be ring fenced and a for services to be "audited" by young people in order to ensure minimum standards are adhered to.
The call comes a week after the government announced it will publish a strategy for youth services.
Speaking at the Ambition UK 2016 conference in Milton Keynes, youth minister Rob Wilson said a youth policy statement intended to cover the three-year period up to 2020 will bring together a "clear narrative and vision" for how best to help young people.
Fran Sullivan, chair of Unite's Community, Youth and Playworkers' section, said: "Youth work is the glue that binds communities together; our members liaise with the police, social workers and a range of health professionals from community nurses to clinical psychology on a daily basis to assist young people through often traumatic times."
Unite national officer Colenzo Jarrett-Thorpe said: "The axing of more than 3,000 youth work jobs needs to be reversed to enable a renaissance for children and young people's services.
"We need one qualified full-time youth worker for every 400 young people aged 13 to 19 in each local authority.
"A crisis is being stoked up among our young people, whether it is employment or mental health services. These issues need to be addressed in the review announced recently by the minister for civil society, Rob Wilson.
"It is time for the government to step up to the plate and replace warm words with action for all young people struggling with employment, housing and abuse issues.
"Next week's Autumn Statement gives chancellor Philip Hammond an excellent opportunity to give a financial boost for this much-needed and valued service."
