SMALL firms in the south have today been given a wake-up call over the national drive to root out illegal workers.

Bosses - already wading through other red tape - are now expected to make extra checks on prospective staff in order to have a defence against costly prosecution.

Employers need to check and copy either a passport, national identification card, UK residence permit or application registration card from each person they intend to employ.

The document in question must permit the holder to work in the UK.

Alternatively, employers are able to check and copy a specified combination of two other identification documents, such as a National Insurance card and a full UK birth certificate, or a P45 certificate and a certificate of naturalisation stating that the holder is a British citizen.

Any employer who is unable to produce copies of the necessary documents will not be able to establish the statutory defence against prosecution for employing an illegal worker and could face a £5,000 fine for each person employed illegally.

Yvette Craig, sales manager for Southampton employment law experts Associa Employment Service, said the changes mean even the smallest local firms have to ask every individual they intend to employ for specific identity documents.

She added: "Local employers will be at risk if they simply get an employee on the basis of that person's claim to be allowed to work here and then fail to carry out further checks."

Hamish Masson, the Institute of Chartered Accountants' regional manager, also warned employers to be on their guard over forged documents.

The Home Office has produced a guide for employers which can be obtained by calling the helpline on 0845 010 6677.

Prosecutions take place under the Asylum and Immigration Act.