Social Justice Network spokesman Jamal Daoud says the immigration department has stopped negotiating with the protesters, who have been on a hunger strike since Wednesday.
He says the detainees are very weak and distressed.
A Department of Immigration spokeswoman says the department is providing water for the detainees but they would have to come down to get food.
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The protest is now in its sixth day after a riot by up to 100 detainees left nine buildings at the detention centre gutted by fire.
A rally planned by the Refugee Action Coalition will be held outside the centre at noon today.
The organisation's Nick Riemer says the recent unrest in Villawood makes it extremely urgent to show community support for refugees.
He says it's an extraordinary irony that both Labor and Coalition politicians talk of refugees having committed crimes, saying the damage to property on Wednesday is nothing compared to the brutalisation of innocent lives caused by mandatory detention.
