A six-day protest against an immigration removal centre near Gatwick airport has got under way with more than 100 people setting up camp.
Protesters have begun arriving at the No Borders camp in Balcombe
About 200 more campaigners are expected to join in over the weekend at the "Gatwick Area No Border" camp in a field in Balcombe, West Sussex.
Organiser, the No Borders UK network, opposes all immigration control.
The 420-bed Brook House detention centre is set to open in 2008 next to the existing 136-bed Tinsley House.
Crawley Borough Council granted planning permission for the deportation centre last November.
The protest camp will involve meetings, workshops and off-site events including the handing out of newspapers and other campaign material.
Organisers have said they will try to make the protest safe, peaceful and legal.
A spokeswoman for No Borders said: "By raising awareness of the suffering caused by immigration prisons, we hope to ramp up a local and national campaign against the new detention centre being built near Gatwick Airport."
A spokeswoman for the Border and Immigration Agency said Brook House was at the centre of its strategy to remove people with no right to remain in the UK.
"By doubling our enforcement resources we have been able to remove almost 3,000 foreign national prisoners in the past 12 months," he said.
"We removed a record number of failed asylum seekers in 2006.
"While it is always preferable for those with no right to remain in the UK to return home voluntarily, those who choose not to play by the rules should be in no doubt we will do everything in our power to send them home."