Mark Russell, the chief executive of The Children’s Society, said that dangers did not disappear during lockdowns, but were just better hidden.

He said: “When schools are closed, children are out of the line of sight of teachers, extended family and others who can spot signs that all may not be well.

“Predators adapt. With children spending more time online because of lockdown and home schooling, in our services supporting children who have been sexually abused or groomed to commit crimes such as trafficking drugs, we’ve seen more who have been groomed online.”

Mr Russell said that school closures also inevitably impacted on children’s mental health, with figures suggesting more than one million young people described themselves as being unhappy with their lives during the first lockdown. 

Children ‘must not vanish from view’

He added: “Government leaders undoubtedly face some very difficult decisions. As they make them, it is absolutely vital that the safety and mental health of children are paramount in their minds.

“If schools do have to close, then we would urge councils to ensure contact with families from schools and social services continues, so that children do not vanish from view.”

Richard Cooke, the chairman of the West Midlands Police Federation, said when children were not in the classroom, gangs were quick to pick off and exploit the vulnerable.

He said: “When schools are closed there is a void that is filled by gangs. We see big rises in County Lines dealers and knife crime. Wherever there are drugs, there are knives. 

“One of the best ways for the police to pick up on when youngsters are being drawn into the margins of criminal gangs is through teachers and schools. Without them it is incredibly difficult to spot what is happening before it is too late.”