Hundreds of migrants and refugees based at the Jungle camp in Calais have been ordered to leave next week or face eviction, according to local aid workers
State authorities have given them until 7pm on Tuesday to leave their makeshift homes in the southern part of the squalid site.
Up to 1,000 people who have fled war, poverty and persecution are reported to be affected by the plans, but local aid workers say the figure could be much higher.
Pascal Froehly, who volunteers for the relief organisation Caritas, spoke of his concerns of heightened tensions being created if bulldozers move in to level the site.
He said: "I find it extremely annoying and unfair to move these people away from what they have created, including churches, shops and restaurants."
Mr Froehly said the plans to move them to heated containers elsewhere in the camp offered the migrants and refugees no chance to socialise, adding: "It's just a bed for them."
Mayor of Calais Natacha Bouchart said the dismantling of the camp would keep migrants and refugees away from activists bent on causing disruption.
She said it was a "sensitive situation" that required "necessary firmness". And she added the conditions endured at the Jungle were "unworthy of human nature".
Plans to move people to heated containers in the camp and centres around France were announced by Prefect Fabienne Buccio, the top official in France's northern Pas-de-Calais region.
Ms Buccio said this month: "It's time to tell the migrants of Calais who live in undignified conditions and give Calais an image that isn't dignified either, that we have a solution for each of you."
An estimated 4,000 migrants and refugees from countries including Syria, Afghanistan, Eritrea and Iraq are currently based within the sprawling Jungle.