31.19.8 Summary from the UKBA operations enforcement manual

IOs have powers to question people away from their point of entry to the UK about their identity and
leave status, on a consensual basis, following the formation of a reasonable suspicion that an
immigration offence has been committed. In addition, just because an immigration presence on a
crime reduction operation or street operation is lawful, it does not mean that IOs will automatically
be able to legitimately stop and question individuals. On a crime reduction operation, the referring
officer will need a reasonable suspicion that that person is an immigration offender. On a street
operation, there still needs to be a reasonable suspicion that that individual may be an immigration
offender before initially stopping, questioning (with the consent of the person stopped) and where
appropriate, subsequently arresting.
Only when an IO has formed a ‘reasonable suspicion’ that an individual is an immigration offender
may he lawfully seek to stop that person on a voluntary basis with a view to asking him questions
about identity and leave status. Where this is the basis for the stop, Singh v Hammond and an IO’s
powers under Schedule 2 of the Immigration Act 1971 Act to examine the person about their
identity and leave status will provide the lawful authority to do so.
An IO has no power to stop a person who refuses to do so unless they have other information in
their possession at that stage amounting to grounds for arrest under one of the relevant arrest
powers at Part III or Schedule 2 of the Immigration Act 1971.
An IO must not engage a person on the basis of their appearance, race, colour, ethnic origin or
nationality. To do so would amount to unlawful discrimination under the Equality Act 2010.