Immigration: Know your rights
Immigration checks are not allowed on a speculative basis. Border Agency staff and police must have a valid reason to believe that you are an immigration offender before they can stop and question you.
Race alone is not enough reason for a spot-check, according to the Equality Act of 2010.
If you are stopped you do not have to answer any questions and you can simply walk away.
Immigration officers must identify themselves and show a warrant card, explain why they wish to question you, inform you that you don’t have to answer any questions and that you are free to leave at any time.