A holding facility for failed asylum-seeking families to stay in before they are deported from the UK should take in more people, a watchdog has said.
The Independent Family Returns Panel said Cedars centre in Pease Pottage, West Sussex, should help more families.
It wants Barnardo's, which runs welfare and social care services there, to lift its limit of taking no more than 10% of all families returned each year.
But the children's charity insisted its use should be exceptional not routine.
The watchdog, which advises the UK Border Agency (UKBA), said allowing more families to stay at the holding facility for up to a week would help them come to terms with their return.
It said Cedars operated "well below capacity" and questioned whether the current admission policy was in the best interests of families.
"Barnardo's have published 'red lines' as a condition of their involvement in the family returns process," it said in its first annual report.
"One of which is that no more than 10% of families returned each year are accommodated and returned through Cedars.
"This creates an inherent dilemma within the process. It is appropriate that the detention of children is kept to an absolute minimum, indeed this is a government priority.
"However Cedars appears to be successful in helping families, especially children, to come to terms with return.
"It is the view of the panel that more families would benefit from a stay at Cedars as part of their return plan."
But Barnardo's has refused to change its criteria, saying it had always been agreed the centre would be used by small numbers for a short time and as a last resort.
Chief executive Anne Marie Carrie said: "Ideally the pre-departure accommodation would not need to exist at all as UKBA should be doing everything it possibly can to incentivise families to make a voluntary return, which is ultimately preferable to an enforced one.
"Families should only be referred to Cedars as a matter of exception, not routine, which is why we will be sticking by our red line that Cedars should be used in no more than 10% of total family returns."
She said Barnardo's would continue to campaign tirelessly for children and families seeking asylum.
The centre includes apartments where families have their own lounge, kitchen, bathroom and bedroom with furnishings that cater for children.