Refugees squatting in a shanty town outside Calais in northern France ignored an official order to evacuate part of their camp, hoping a court hearing on Tuesday will halt its demolition.

Thousands of people fleeing poverty and war in Africa and the Middle East have taken shelter in the makeshift camp known as the "jungle" after attempts to force their way into Britain via the Channel Tunnel were foiled by French police.

Under pressure to reduce the migrant presence, local authorities said on February 15 that up to 1,000 people out of an estimated total population of 4,000 would have to leave the southern part of the camp within a week.

The deadline expires on Tuesday at 8pm local time, after which authorities will be empowered to remove remaining tents, if necessary by force.

Interior Minister Bernard Cazeneuve said residents would be evacuated in a "humanitarian operation" and there was sufficient alternative accommodation for all either in the region or elsewhere in France.

"We have nowhere to go so we will just wait," Aziz, 42, from Pakistan, told Reuters. He and 16 other refugees sleep on the floor at the rear of a wooden hut converted into a shopping booth.

Mohammed, 33, fled Afghanistan five months ago and works in a small coffee house nearby with a sign marked "Kabul cafe."

"I hate it here, but at the same time this is where we live now, where we socialise, we don't want to go to a closed space that will be like a prison," he added, referring to a state-run shelter made of converted shipping containers that opened last month.

Charity activists on the ground say the official numbers are understated and closing half of the "jungle" will force some 3,400 people to leave, including women and between 300 and 400 unaccompanied minors.

"We have used a strict methodology based on waste and water consumption", said Maya Konforti, who works with local association Auberge des Migrants (Migrant Hostel).

"An evacuation of the southern part of the jungle will put an end to most of the services migrants enjoy in the camp such as bars, shops, but also schools and churches, places of life," she said.

On February 1, there was a public outcry following the demolition of a church and mosque in the Calais jungle.

St Michael's, the makeshift chapel that featured in BBC's Songs of Praise last year, was bulldozed along with a mosque because they were in a newly created "buffer zone" – a safe space between the camp and public roads.

The Calais Prefecture had previously agreed that the mosque, church and a school would not be affected.

Local authorities say migrants moved under the latest plans will be offered places in other refugee centres across France or moved to the state-run shelters which have no toilets and no direct water access.

The container park has around 500 spare places out of a capacity of 1,500, the authorities say.

Eight NGOs filed a request for a temporary injunction to halt the evacuation with the administrative court in regional capital Lille last week. A hearing is due on Tuesday afternoon.

Regional government representative Fabienne Buccio told journalists on Sunday she would comply with any judicial ruling but that the "jungle" had to diminish in size.

Additional reporting by Reuters.