The Home Office has won its appeal against a landmark ruling allowing four Syrian refugees living in the "Jungle" camp in Calais to come to Britain.
An immigration judge ruled in January that the three teenagers and 26-year-old man with mental health problems should be brought immediately to the UK and reunited with their families.
It was hailed as a landmark decision that could pave the way for many other unaccompanied minors to come to the UK from refugee camps in Europe.
But while the Home Office is not seeking to deport the four Syrians, it appealed against the ruling because it feared it could set a legal precedent and undermine Britain's control over its borders.
All four have been reunited with their families in various parts of the UK, two of them have been granted refugee status in Britain while the other two are still waiting for a decision to be made.
George Gabriel, from Citizens UK, the charity that has represented the children, warned the ruling will lead to further delays and refugee children will be driven into the hands of people smugglers.
Under a law called Dublin III, asylum claims must be made in the first country the person reaches, but a child refugee can have their claim transferred to another country if they have relatives lawfully living there. The ruling in January was made after lawyers for the Syrians argued that they had an entitlement under the Article 8 right to a family life to be reunited with family in the UK.
Criticising the decision, Gabriel said: "Today is a great day for bureaucrats because it means that the letter of the process will have to be followed despite the clearly unacceptable wait this leaves refugee children facing.
"We fear this means many will take the situation into their own hands, choosing between people traffickers on the one hand and train tracks on the other."
Handing down their judgment, Court of Appeal judges Lord Justice Moore-Bick, Lord Justice Longmore and Lord Justice Beatson stated that bypassing the Dublin III Regulation "can only be justified in an especially compelling case".
The Bishop of Barking, Peter Hill, a spokesman for Citizens UK, said they are "disappointed" with the result which will leave refugee children relying on volunteers to help them come to Britain.
He said: "The Government has a legal and a moral responsibility to ensure that refugee children who have close family members in the UK are granted safe passage."