Young people are facing "unprecedented threats" to their futures from the Covid-19 pandemic, and should be prioritised, says a group of charities.
Children are "in an eerie world, full of uncertainty", say 146 organisations.
In a letter to the prime minister, they urge government to put children's needs on a par with health and the economy to stop their life chances being derailed.
The government said that "throughout the pandemic we've prioritised children's safety and wellbeing".
The charities and other bodies, including Action for Children, Barnardo's, the National Children's Bureau, NSPCC, the Children's Society, Unicef UK and the Child Poverty Action Group, say Covid-19 "threatens to cast its shadow" over the young for years to come.
"They do not know when they can go back to school. They worry about when they can see friends and family. They are anxious about family finances," they warn.
"We know this uncertainty and worry will lead to anxiety and mental health problems.
"We know closed schools will damage the educational attainment and life chances of children - the poorest the most.
"We know black, Asian and minority ethnic communities will be hit the hardest.
"We know there is more financial hardship to come."
The charities say the voices of children, young people and families must be at the heart of the recovery and rebuilding process and there must be renewed investment in the services they rely on.
'Put children first - they're the Covid children'
Jennifer from Bristol, a mother of two children with disabilities, told the BBC the past few weeks have been very difficult for her family.
She says one of her sons has had regular panic attacks in the night, while the other recently said: "I want to throw myself out of a window, I just want this to be over."
Her younger son has been so scared that he has refused to go out in the garden "as he thinks he's going to catch something just from being outside".
"It's a real fight for me to try to get him to go out and get some fresh air."
With the help of Action for Children, she now has a trampoline in the garden to encourage him to venture outside.
Jennifer says there are times when feels she has let her children down and takes herself off to the shower when it all gets too much.
"No-one can hear you crying in the shower, can they? Then they don't know. It's not good for them to see you're not coping."
She feels the needs of children and families have been overlooked during the pandemic.
"We came out and clapped for the NHS, for carers, but did anyone think of the children - they're the Covid children - and how their little lives have been turned upside down and their routines ruined?"
Her message to the government is simple: "They need to start putting the children first, and their mental health."
The charities say: "The government, understandably, has so far focused on the immediate health and economic consequences.
"It's now time for the nation to put a strong, protective arm around its children, to stop childhoods being disrupted and life chances being derailed."
A government spokeswoman said: "Schools and colleges have remained open to vulnerable children and we're keeping in touch with those most at risk.
"We've expanded frontline charity support and provided new resources for schools and teachers to support children's mental health."
The government has announced a catch-up package for lost teaching time, an investment plan to improve schools and college buildings and will continue to invest in early years education, she added.
The letter to the prime minister comes as a survey by Barnardo's suggests the lockdown has affected the mental health and wellbeing of young people.
The poll of 4,000 UK children and young people, aged eight to 24, found that a third had experienced an increase in stress, loneliness and worry.
Nearly three-quarters (74%) said they missed going into school or college.
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