Thousands of children with depression, anxiety and eating disorders are being denied treatment because of a lack of urgency by ministers to address a crisis in mental health services, health experts have said.

The criteria to get treatment are now so high that one youngster in five referred by a GP is turned away because they are not ill enough.

Government announcements of an anti-stigma campaign and a study on the prevalence of mental illness failed to address the immediate breakdown in services, they said. Even the promise of £1.25 billion over the next five years has been staggered so that only a fraction would be spent this year.

The experts include Tanya Byron, the author of Time to Mind, The Times’ child mental health campaign manifesto, and its three other signatories: Sarah Brennan, chief executive of Young Minds; Peter Hindley, a psychiatrist working with children, and Isobel Heyman, a professor of child and adolescent psychiatry and the chairwoman of London Child Mental Health.

Time to Mind, published in March, called for greater investment in services and early intervention. However, there are signs that mental health will not be considered a priority in the spending review.

Professor Byron said that the extra cash would lift the budget for children’s services only from 6 per cent of the total mental health budget to 8 per cent, falling short of the step-change required.

“Five-year spending plans and new money is fantastic, but it all takes time to set up. Meanwhile one in five children is being turned away for treatment even after they have been referred. There feels like a total lack of urgency for treating children,” she said.

She added that she doubted ministers would adopt the same approach for a physical health crisis.

The n umber of emergency hospital admissions for young people with psychiatric conditions reached 17,278 last year, double the number four years ago. There were 15,668 admissions of young women aged 15 to 19 for harming themselves, compared with 9,255 ten years ago.

Dr Hindley, a former chairman of the Royal College of Psychiatrists’ faculty of child and adolescent psychiatry, said it was not clear that the extra funds would be ring-fenced and end up in the right services for children and young people.

“We are miles away from genuine parity of esteem between mental health and physical health services,” he said.

Ms Brennan said the money earmarked before the election was inadequate to address the problem facing young people, noting that only £143 million of the promised £250 million a year increase would be spent this year. “We need reassurance that the underspend will be made up in the following years,” she said.