File on 4 sets off on a new series to find the forgotten children of Europe's refugee crisis.

As winter sets in, Phil Kemp heads to Greece in search of the teenagers who have arrived alone from Syria and Afghanistan, living by their wits on the streets of Athens.

The controversial deal struck between the EU and Turkey to return migrants who don't claim asylum or who have their claims rejected - and the closing of borders with Greece - has been blamed for making the situation worse for many migrants who now find themselves in limbo in Greece. The millions pledged by the EU don't seem to be bringing relief on the ground either.

The programme hears from the lucky ones who have found spaces at shelters for unaccompanied children in Greece's capital. Here they are fed, clothed and supported in their legal cases.

Others, on the island of Samos, are celebrating securing asylum in Greece. But most children on the island are not celebrating. They feel stuck in a system that cannot cope and held in a country that was meant to be a transit point, not a place to stay.

Increasingly the locals in Samos don't want them to say either. Tensions are flaring in the area around the vastly overcrowded camp, with Golden Dawn active nearby. Around 3,000 residents turned out to protest about their sense of abandonment by the Greek government and the EU. Local officials describe the island as 'trembling on a bridge above troubled water.'

With an estimated 2300 unaccompanied migrant children in Greece, more than half of whom are on the waiting list for shelter, File on 4 asks whether the EU is doing enough to care for those most in need of protection.

Reporter: Phil Kemp