By Baptiste Becquart and Zoe Leroy 5 hours agoCalais (France) (AFP) - Six migrants were given a month in prison on Monday for occupying a ferry in northern France, while charities warned thousands could be affected by plans to evict half of the "Jungle" refugee camp in Calais.

The migrants from Afghanistan, Sudan and Syria were convicted alongside two activists, who received fines from the court in Boulogne-sur-Mer for their part in a protest last month calling for Britain to allow asylum seekers in.

Towards the end of the protest in the northern port of Calais, some 150 people broke through a barrier around the port and about a third managed to board the "Spirit of Britain" ferry. Several hours later, police removed them, arresting 24 migrants and 11 members of the No Borders activist group.

The convictions came a day before a deadline of 1900 GMT Tuesday set by local authorities for people in the southern half of the Jungle migrant camp to leave.

The local government says the demolition will affect between 800 and 1,000 residents of the grim camp, which stands on a former toxic waste dump on the outskirts of Calais.

It estimates there are currently some 3,700 people living there, all of whom are hoping to sneak aboard lorries heading for Britain.

But according to charities working in the camp, who say they have done a census, there are around 3,450 people living in the southern part -- including 300 unaccompanied children.

The demolition "risks displacing migrants to other camps in the region, which is only moving the problem somewhere else," said Vincent De Coninck, a volunteer with Caritas.

Conditions in other camps along the northern French coast are even more dire than those in the Jungle.

- 'By persuasion' -

French Interior Minister Bernard Cazeneuve said the eviction would be done "progressively, by persuasion and with respect for people's dignity".

But several charities are challenging the eviction order, and a judge is due to visit the Jungle on Tuesday before giving a verdict later in the day.

"I don't have anywhere else to go," said John, a 28-year-old Sudanese migrant in the camp.

"We don't want to leave Calais because we don't want to get further away from England, which is still our goal."

His friend Ahmed added: "We know we won't be here forever, thank God, but for the moment we don't have any choice."

Local government head Fabienne Buccio said Sunday that "everything will be done" to avoid the use of force in clearing the camp.

"The dismantling should start on Wednesday and security forces will not be used if everyone plays their part," Buccio said.

In an earlier statement, the Calais town hall claimed it was acting in response to "abuses" committed by migrants that had led to "an aggravated level of tension" in recent weeks.

It said camp residents were throwing stones and other projectiles at lorries and security forces on a daily basis, but also condemned members of far-right groups who loiter outside the Jungle to beat up migrants.

- Celebrity support -

The French authorities have been gradually trying to shut down the Jungle, encouraging residents to head for proper centres elsewhere in France.

However, many of the residents have family or community ties to Britain and are reluctant to give up their dream of crossing the Channel.

A campaign spearheaded by celebrities such as actors Jude Law and Benedict Cumberbatch has called on the British government to let children from the camp be reunited with families in Britain and take responsibility for the "humanitarian crisis" in the Jungle.

Those being pushed out of the camp can go to one of around 100 accommodation centres elsewhere in France, or into refitted shipping containers set up nearby.

The containers have not proved popular with migrants, who say they lack communal spaces and restrict their movements, while local charities say they fail to meet international standards.

Migrants jailed for storming France ferry as 'Jungle' demolition looms