A 2009 report by the National Audit Office cited lack of detention space to support the asylum process.

The agency has over 3000 detention spaces in removal centres run by private contractors or the Prison Service.

And the shortage of detention space for families has led to an increase in the number of unrelated illegal immigrants who say they are families.

Officials said the case might not be resolved for a year, and the limited detention space could be better used.

Immigration officials said their ability to arrest illegal workers was limited by the lack of detention space.

There was so little detention space that many illegal immigrants, even those with weak asylum cases, were routinely released on bond.

Officials said the halt had resulted from a shortage of detention space.

They found more detention space near courthouses, reducing the need for transportation from distant precinct houses.

Most of them have been released simply because there is a shortage of detention space.

Congress also provided money to hire 1,000 Border Patrol agents and to build detention space for 4,000 illegal immigrants.