According to the Home Office, with regard to the legal basis for identity screening and immigration checks at airports and sea ports, as carried out on passengers travelling between Northern Ireland and Great Britain, "Immigration Enforcement officers may arrest without warrant anyone they have reasonable grounds to suspect has committed an immigration offence and/or may be liable for removal directions." Section 31.19.3 of the Enforcement Instructions and Guidance (part of the visas and immigration operational guidance), relating to the case law "Baljinder Singh v. Hammond", said "Any questioning must be consensual. The paragraph 2 power to examine does not include a power to compel someone to stop or to require someone to comply with that examination. Should a person seek to exercise their right not to answer questions and leave, there is no power to arrest that person purely on suspicion of committing an immigration offence."