Video report by ITV News National Editor Allegra Stratton
There are hundreds of unaccompanied children in the Calais jungle migrant camp, but ITV News has discovered the extent of the struggle in identifying those eligible to be re-homed in the UK.
Charities believe 378 of them have a right to live in Britain.
The Home Secretary Amber Rudd said on Monday that a delay by French officials in establishing who those children are would end this week.
She told the Commons the government would move with "urgency" to bring them to the UK before the camp is closed by French authorities, which they say will happen by the end of this month.
On Friday, the Home Office arrived at the camp to begin processing the children.
Child Refugee Advocate Sue Clayton has also travelled there to help.
Over five days she has made her own list of 78 unaccompanied children. Some of them are in their late teens. Others are much younger - and visibly frightened about their plight.
"The ones I'm worried about are these 13- and 14-year-olds," she said, pointing at a list of hand-written names on a notepad.
"If the camp's going to go they're the ones who will be at risk."
We met one such boy, 15-year-old Jona. Like many, he is all alone in the Calais jungle. He is a Christian Eritrean, and because of legislation rushed through this year he may be eligible to come to the UK. But working out who meets this criteria isn't easy.
At a nearby cafe, where children as young as nine sit in hope, a group of eight London lawyers gathered this week to try to establish their legal rights.
With the camp about to be demolished, time is against them.
One of then, Duncan Lewis, said: "There are a number of lawyers and a number of organisations trying to help children who are effectively refugee children in Europe who are in Calais but benefit from what's called the Dubs Amendment which is effectively a UK Act that's been passed which should allow for refugee children to come to the UK.
"We're trying to prepare those applications to put to the Home Office and say to them you need to bring these children over."
More than 80 unaccompanied children have been accepted for transfer under the Dublin regulation so far this year.
The EU's Dublin regulation states asylum seekers must make an initial asylum claim in the first country they reach, but can apply for asylum in another country in other circumstances, for instance in countries where they have family members.
The amendment by Labour peer Lord Dubs committed Britain to accept at-risk unaccompanied child refugees from Europe.
Ms Rudd said this week up to 300 unaccompanied children would be re-homed in the UK.
But first the authorities need to find those eligible, but frightened and vulnerable minors, hiding in the tents of the Calais jungle. And it's not proving easy.