A British court has ordered that four Syrian refugees living in "The Jungle" should immediately be brought to the UK to live with relatives in a "groundbreaking judgment", the Refugee Council has said.
The case could set an important legal precedent that could allow many other refugees wanting to cross the Channel from Calais to come to Britain.
The young men - two teenagers, a 17-year-old and his mentally ill 26-year-old brother - all faced "intolerable" conditions in the sprawling camp and were desperate to be reunited with their siblings in the UK, the Immigration and Asylum Tribunal in central London heard.
They have a legal entitlement to come to the UK to seek asylum because their relatives are already legally living here.
However, under EU law known as the Dublin regulation they would only be allowed to join their relatives in Britain if they had already applied for asylum in France.
But lawyers in Britain successfully argued that because of bureaucratic failings in France and the refugees' entitlement to a family life under Article 8 of the European Convention of Human Rights, they should immediately be brought to Britain and their asylum applications processed here.
Refugee Council policy manager Judith Dennis said the judgment was a "welcome light" for refugees seeking protection in Europe and who are trying to reach relatives.
She said: "Everyone has the right to live in safety with their loved ones. European governments must work together to ensure families are reunited safely and speedily, especially when it comes to children and other dependent family members."
The Home Office had fought the application and plans to appeal it, the Refugee Council said. But it is understood the order will apply immediately meaning the four refugees can travel over from Calais now.
The judgment, to be handed down in full at a later date, effectively means French authorities will be bypassed as the applications are handed over directly to the British.
Michael Fordham QC, representing the applicants, told the hearing on Monday the case could open the door to other applications from refugees at the camp hoping to come to Britain.
He said: "It will apply to others - certainly, I would say, any unaccompanied minor in this camp with a sibling in the UK. And I don't shrink from that.
"You are only deciding these cases so you know things like how long they have been there and the assessment of their needs.
"I'm not asking you to give a ruling that will be some general protective principle that does not regard those things."
But he added: "Suppose you have only been there a week, my argument is the same. This is intolerable for a day."
The court heard that all the men have been traumatised, that several of them suffer from post traumatic stress disorder and that squalid conditions at the camp are aggravating these health problems.
Mr Fordham said the office of the UN High Commissioner for Refugees said the camp amounted to "an undignified and intolerable situation". The United Nations special representative on migration Peter Sutherland branded the camp "a stain on Europe" and "living hell", the court heard.
George Gabriel, from campaign group Citizens UK, said: "This judgment highlights that there are safe, legal routes to reconnect families using the Dublin III regulations, and we hope will allow other families to be reunited."
He added: "Now government and the French authorities must act to ensure no more children are driven into the hands of people smugglers or become so desperate they take terrible risks to reach the safety of the UK.
"We know this is just the start of work to ensure the most vulnerable are protected and are pleased with this positive outcome; it will help us to continue to fight for justice for those who are in most need through no fault of their own."
Karl Pike, from the British Red Cross, said the government needed a "more ambitious" response to the refugee crisis, saying "a 'business as usual' approach won't work".
He added: "Instead of putting obstacles in the path of people who have a right to be safe with their families, there must be more accessible routes to safety for refugees."
Steve Symonds, from Amnesty UK, added: "It should be a matter of shame that these desperate family members had to resort to the courts.
"Despite the squalor and misery of so many in Calais and Dunkirk the UK government has doggedly maintained its refusal to share responsibility with France and other EU countries - even in the case of refugees with family long settled in the UK, including British citizens."