Is it lawful to ask a job applicant if he or she requires permission to work in the UK?
Yes, an employer can ask a job applicant if he or she requires permission to work in the UK, as long as all job applicants, regardless of colour, race, nationality, or ethnic or national origins, are asked the same question. Asking the question only to certain applicants based, for example, on their accent or skin colour could amount to unlawful race discrimination.
All employers are subject to a legal requirement under the Immigration, Asylum and Nationality Act 2006 to check that anyone to whom they offer employment has the right to work in the UK. The Government has published guidance to assist employers with how best to do this while avoiding unlawful discrimination (Code of practice for employers: avoiding unlawful discrimination while preventing illegal working).
One way for employers to deal with this issue is to state in all letters inviting job applicants to interview that they will require documentary evidence of the applicant's right to work in the UK. It is advisable for employers to inform all applicants that it is the organisation's policy to require all applicants to comply with this request. At the interview itself, the employer should request sight of, and make copies of, the relevant documents.