Dear all I understand the legal obligations of an employer for mobile workers however, I cannot locate a document which defines a 'mobile worker'. Could anyone point me in the right direction as to where I can find a HSE document which has this definition. I require this document due to a dispute with the client. Thanks in advance..

I can't recall seeing such a document, however you might want to try 'transient' worker in your search. The definition of mobile or transient worker is problematic in itself.