The Jungle refugee camp could be closed imminently after a French court rejected an appeal from aid groups to delay the clearance.
French authorities are expected to empty the migrant camp in Calais in the coming weeks and dismantle it by the start of winter.
A Lille court has rejected a request from aid groups to postpone the closure, arguing that authorities are not ready to relocate its residents.
Charity groups warned that many of the migrants do not want to stay in France and may set up camp elsewhere to continue trying to cross the English Channel to Britain.
The French interior and housing ministers welcomed the court's ruling and said the camp should be dismantled before winter sets in.
Migrants and refugees in the shanty town are being relocated around France or deported ahead of the closure.
Coach-loads of families are being taken by bus out of the slums to start new lives elsewhere in France.
Young children were among those who boarded the coach on the camp's fringe before it took them to new communities in the south of the country.
No date has been announced for the demolition of the camp, which is believed to be occupied by between 6,000 and 10,000 people.