The government should expand its mental health plans to encompass all schools, the children’s commissioner for England has told MPs.

Anne Longfield this afternoon warned the Commons Public Accounts Committee about the “huge number of children who are not getting help and whose problems are being left to develop into more serious crises”.

The committee asked her about the government’s Transforming Children and Young People’s Mental Health Provision Green Paper, which was published last year.

It includes plans for mental health teams working in and near schools, and encouragement for every school to appoint a designated senior lead for mental health.

However, the government has come under fire from MPs and charities for only planning to roll out the plans to 20 to 25 per cent of the population by the end of 2022-23.

Ms Longfield said the plan has “really important initiatives and interventions that will make a huge difference”.

Mental health: 'Let's put a trained professional in every school'

However, she said that “actually it will only take us to about a fifth or a quarter of all schools,” adding: “I’d like to see a trained professional in every school. Just something we can rely on and know.

“If we can do that we can stem the problems developing so you can actually bring down the number of children who are needing to go for more serious help.”

Asked what one thing she would do to improve the situation, Ms Longfield said: “I would quadruple the Green Paper plans to get to every school and provide that specialist help so there weren’t those gaps and black holes between the [teachers] who see the children and the specialist help.”

She said that if she was health secretary, she would want “a high-level, high-priority plan which is very ambitious for a seismic change, that sets out to actually provide the help for all children who need it – not a fifth, not a quarter, not a third, all children who need it over a period of time.

“If [the wait] has to be 10 years, it has to be 10 years, but 10 years is a long time for children, as is five."

She said such a plan would set targets for all children to get help – not just some children, or those with certain needs – and would reduce waiting times to four weeks.

A Department for Education spokesperson said: “We know schools need specialist support to help deal with the mental health issues faced by pupils, which is why we are investing an additional £1.4 billion in children and young people’s mental health services.

“In addition, our Green Paper proposals will fund new teams of trained staff to work collaboratively across schools and specialist services.

"This significant new workforce will work with mental health professionals to provide the right support quickly and will complement the services already provided by existing support staff, such as school-based counsellors.”