Almost all of the children who have spent time in the so-called 'Jungle' camp in Calais for refugees have a post-traumatic stress disorder (PTSD). Following delays in transfers out of Calais or being housed in storage containers has left many youngsters with deteriorating mental health. There are also reports of youngsters sleeping rough around the periphery of the camp.

Staff at Citizens UK say they have been sent suicidal text messages from the children, since the demolition of the refugee camp. Dr Susannah Fairweather, a psychiatrist who compiled evidence for the charity, said there had been a "significant deterioration in the children's mental health, including a risk of suicide.

"As a consultant psychiatrist who has assessed children both in the 'Jungle' and once they have arrived in the UK, I know the children living there experienced horrific traumas both in their home countries and their journeys there," she told the Guardian.

"Of the children who underwent psychiatric assessment, all of them presented with psychiatric symptoms, with approximately 90% meeting the criteria for a recognised psychiatric disorder, such as PTSD and depression."

Citizens UK state that of the 40 children being taken care of, 90% say they have "increased anxiety" and over 30% report having suicidal thoughts.

Around 15% of the lone children in Calais have now been transferred to Britain and 1,600 are now scattered all over France in temporary accommodation. On Friday (4 November), the government said that no more children would be coming to the UK this weekend.

"The young people who have lived in the unstructured, informal camp for a prolonged period of time find it particularly difficult to adjust to life in more ordinary circumstances," Fairweather said. "A temporary transfer to accommodation in France will only serve to exacerbate this.

"The longer they are met with uncertainty from authorities about their situation, the less likely they are to trust professionals. This increases the risk that they will use unofficial systems to enter the UK, such as people smugglers."

Many of the children are in limbo as diplomatic tensions between Paris and London continue. French President Francois Hollande is demanding that Theresa May "take their share [of responsibility] to welcome them in Britain". However, Home Secretary Amber Rudd said it was the duty of the French government to "properly protect" the children.