An urgent High Court hearing has been ordered into claims of inhumane conditions at Yarl's Wood detention centre, Bedfordshire.
Public Interest Lawyers (PIL) said the case concerned the treatment of women and children involved in asylum and immigration claims.
Mrs Justice Davies gave permission for the hearing after seeing documents supporting the application, said PIL.
The Home Office says all detainees "are treated with dignity and respect".
It said it would not comment on this particular legal action until the case had finished.
Serco, the private company that runs Yarl's Wood, has described the allegations of inhumane and degrading treatment as "unfounded and untrue".
Public Interest Lawyers is a public law firm specialising in domestic and international human rights issues.