Lone child refugees stranded in Europe have been left vulnerable to exploitation and trafficking after being failed by the British government, a new report claims.
British ministers were accused of doing "as little as legally possible" to help minors who are unaccompanied or separated from relatives.
The assessment is based on an inquiry led by former Labour MP Fiona Mactaggart and Elizabeth Butler-Sloss, who were co-chairs of the all party parliamentary group on trafficking and modern slavery before it was dissolved when the election was called.
In the forward, they write: "The United Kingdom rightly regards itself as a country which takes care of children.
"But these children, who are not yet here, are facing daily risks and dangers which simply would not be tolerated if they were visible to us all.
"Many put themselves in harm's way because they see no alternative, without trusted adults around them they are vulnerable to exploitation and without access to any legal system and safe routes to come to the UK where many have close relatives, they, instead, depend on criminals and smugglers to make the journey."
Since the clearance of the Jungle camp in Calais in October, the situation for children has become "intolerable", the report warns.
It says the failure of the British and French governments to deliver an efficient, safe transfer to the UK is "unquestionably" fuelling both trafficking and smuggling.
The report claims migrant children in France are subject to tear gassing by police and have to sleep in the woods, while depending on volunteers for food and clothing.
Ministers have repeatedly faced calls to do more to help under-18s who have reached Europe amid the wider international migration crisis.
Earlier this year it emerged that the Dubs scheme, which required the Government to resettle an unspecified number of unaccompanied minors from Europe, would close after 480 were brought to the UK - well below the 3,000 campaigners had called for.
The paper says it had received no evidence to support the assertion that continuing the programme indefinitely will act as a pull factor and encourage traffickers.
"On the contrary, the inquiry concluded that in the chaotic manner in which it was handled on the ground and then abruptly stopped, the Government's own administration of the Dubs scheme has created such a lack of trust in official pathways to safety that it feeds directly into the hands of traffickers," it says.
The inquiry also pointed to evidence that the system of assessing children's eligibility to be reunited with family under a European regulation known as Dublin III rule is being hampered by the "chaotic" situation in areas of Europe with high numbers of migrant arrivals.
Ms Mactaggart said many of the children they met have relatives in Britain.
She said: "The Government needs to make it possible for them to know how to come here legally and get the support and care they need.
"The UK government has failed these children, while claiming it cares about child welfare".
The British Home Office said it was "completely untrue" to say the Dubs scheme was closed unexpectedly.
"The Government remains committed to resettling 480 children already in European countries - a number which was reached following extensive consultation," a spokeswoman added.
She said: "We are committed to supporting vulnerable children who are caught up in conflict and danger. Last year we provided 8,000 vulnerable children with refuge or other forms of leave and by 2020 we will have resettled 23,000 people from Syria, the Middle East and North Africa - half of whom will be children.
"Our strategy is clear, we believe that the most vulnerable children are in the conflict zone around Syria and best way to help them is by resettling refugees directly from the region.
"This is how we can stop traffickers and smugglers from exploiting vulnerable people and children and prevent them from embarking on perilous journeys across the Mediterranean."
A spokeswoman for the French Embassy in the UK said: "The French government has offered a large number of places in the 161 reception and guidance centres throughout the country following the dismantling of the Calais camp and has encouraged and supported the migrants in their process of applying for asylum in France.
"France has co-operated with the UK to reunite nearly 100 of unaccompanied minors with family members in the UK. Those who were not eligible for this scheme are being taken care of in France under the regulatory provisions."
She said "wholesale reform" of the asylum system will enable the processing of asylum applications to be significantly speeded up.