Part of the Home Office's guidance on reuniting unaccompanied child asylum seekers with their families in the UK is unlawful, the High Court has ruled.
Safe Passage, a charity that supports child refugees, took legal action against the Home Office over how caseworkers are told to process requests for lone children to be reunited with family members in the UK.
Under European legislation, child refugees can have their asylum claims transferred to another country if they have family there.
A "take charge request" can be issued so they can travel to that country to be with their family and the claim is assessed there instead.
At a hearing in May, lawyers representing Safe Passage said the Home Office's guidance on how officials process these requests was "causing delay and misery" for children abroad and was unlawful.
In a ruling on Friday, the High Court found that part of the guidance requiring caseworkers to reject a request after two months "even where inquiries had not yet established whether a family link existed and/or whether it would be in the child's best interests to have their claim decided in the UK" was unlawful.
Lord Justice Dingemans also ruled that previous guidance which said that "information should be obtained from a local authority only once the family link had been established was erroneous in law".
The judge, sitting with Mr Justice Dove, said that that guidance, which has since been replaced, "misstated the law" when it said that local authorities would only be asked to undertake an assessment with the child's family "once the family link has been established".
Lord Justice Dingemans said: "This advice established a bright line that the local authority should not undertake an assessment with the family or relative until the family link had been established."
He added: "The fact that guidance directed to caseworkers gives advice which is erroneous in law may lead to unlawful decisions.
"This does not assist UAMs (unaccompanied minors), who may have been wrongly denied the right to re-join family members while the claim for asylum was being processed.
"It does not assist the Secretary of State, who may have acted in breach of obligations and may have made decisions which were unlawful and which are liable to be set aside."
The High Court made a declaration that "specific parts of the guidance" were unlawful, but did not overturn the guidance as a whole as "there are substantial parts of the policy guidance which are not erroneous in law".
Jennine Walker, head of UK legal and arrivals at Safe Passage, said: "Our success in this legal challenge will offer hope to many child refugees desperate to safely reunite with their families in the UK, who were wrongly turned away by the Home Office.
"It should never have taken court action for the Home Office to decide applications fairly and lawfully, and we urge the Government to put these wrongs right by swiftly reuniting those refugee families whose applications were refused."
A Home Office spokesperson said: "We are pleased that the court found in our favour on most of the issues under challenge, and recognised the changes we implemented last year.
"We take the welfare of unaccompanied children extremely seriously and our Immigration Rules provide a number of routes for people to reunite with family members in the UK.
"Our New Plan for Immigration will welcome people through safe and legal routes, whilst preventing abuse of the system and the criminality associated with it."
