A vulnerable former asylum seeker who was an unintentionally homeless person with both mental and physical health problems had a strong chance of successfully seeking judicial review where the local authority had, in deciding that his was not a priority case and refusing interim accommodation, failed to pursue proper inquiries, made procedural errors and acted unreasonably. The judge reviewed the inquiries which should have been made with particular emphasis on the situation of vulnerable former asylum seekers.
(Summary Taken From Jordan Publishing Site)

Anthony Thornton QC sitting as a deputy high court judge stated at [25] that:
“It is significant that the applicant does not have to “prove his case”. The inquiry process is an inquisitorial one and the Code clearly envisages that the case worker undertaking that inquiry will, in a case such as the claimant's, pursue a number of avenues of inquiry…”

Links
Bailii
Nearly Legal Post - Too Soon?
Wikipedia Article on Gatekeeping