The Greens say the federal government's offer to Australia's longest-serving detainee gives the man little hope.
The Immigration Minister, Amanda Vanstone, has written to the 33-year-old Bangladeshi man, offering to let him live in the community but still be in detention.
The Greens senator, Kerry Nettle, says the "residency determination" is of no use to Mr X, who is suffering from a serious mental illness.
She says he is likely to suffer serious mental health problems as long as he remains in immigration detention.
"I think its a cruel non-offer to give him, because it doesn't provide any certainty with his future, and to offer to somebody that they can live in the community when their mental health as a result of their detention is simply not up to it is a cruel situation for somebody to be in.
"It's a Clayton's offer, it's an offer that means nothing."