Dungavel was opened as a detention centre in September 2001
The Catholic Church in Scotland is to mount a national campaign against the detention of asylum seekers' children.
Bishops said it was "a disgrace" that children were being held in prison-like conditions at the Dungavel Detention Centre.
They want Home Secretary David Blunkett to end the practice and find more humane ways of dealing with families.
However, the government stressed that the detention of children was a "last resort".
Dungavel was opened as a detention centre for asylum seekers in September 2001.
'Just like a prison'
It is thought that about a quarter of the 80 people currently detained at the facility near Strathaven, in Lanarkshire, are children.
They include Beriwan Ay, a 14-year-old Kurd from northern Iraq.
She has been there since last summer, along with her 11-year-old brother Dilovan and sisters Nevrooz, 12, and Medya, seven.
The family lived in Kent for four years before being transferred to Dungavel.
It is a disgrace that young children from perhaps the age of five to 14 are held in a prison environment
She told BBC Scotland that her mother and her siblings cried almost every day.
"We ask my mother what is going to happen to us but she says she doesn't know," said Beriwan.
"We can't do anything. It is just like a prison."
Bishop John Mone, the president of the Catholic Church's Justice and Peace Commission, recently visited the centre.
"I feel it is a disgrace that young children from perhaps the age of five to 14 are held in a prison environment and are deprived of many of the rights that are enshrined in the Declaration of Human Rights," he said.
"I have worked with Aids children in Uganda and Kenya and I have tried to help them to have a possibility of living a decent life when their parents are dead.
"I felt 'why am I going abroad and looking after children when there are children in my own country who need my help?'"
There are plans to place a protest petition in every Catholic church in Scotland a week on Sunday.
"I give this my blessing and I hope that many many people will subscribe to this," added Bishop Mone.
Newroz and Beriwan are detained in the centre
He hoped the campaign would lead to "a rising tide of anger" about young children being held in Dungavel.
A spokesman for the Home Secretary said children were only detained as a last resort when there were fears that their parents may abscond while facing deportation.
However, Rosemary McIlwhan, of the Scottish Centre for Human Rights said this was a breach of human rights laws.
"I think they should set up systems within the community which would allow the children to continue going to school and having freedom to play, while ensuring that the adults did not flee," she said.
"For example, something similar to bail where they have to check in at a police station on a regular basis would ensure that the family were not fleeing and ensure the children's rights were protected."