I'm almost sure I remember HSE having some detailed guidance about the circumstances in which agency or temporary workers have to be treated like employees in terms of their health and safety, and stating that this did not necessarily correspond to their tax status.

When I look at their pages on agency and temporary workers now, I just see vaguery. There is a comment about 'if you are genuinely self-employed' but no description of what counts as this.

Has the guidance changed? Has the actual legal status of such workers changed?

It has come to the point for me where contract staff are reluctant to take part in health surveillance or training on the grounds that this could jeopardise their tax standing. Their agency, of course, provides them with nothing.

RR is correct and national insurance and tax law play a VERY BIG part so treat people that U manage as employees re H&S areas advise HR etc. to have a handle on the other areas [but alas in my experience most HR people know about employment law only]

additionally the 'controller' factor comes in here [similar to master - servant] so the more U control somebody [irrespective of what their claimed status is] the more U are responsible and have liabilities etc.

for donkies years most industries have played the game e.g. actors, doctors, construction etc. & people have claimed the benefits of the self employed with regards to tax etc. However the gov has clamped down on construction [However its notable that the gov has not bothered with what is deemed to be the upper class areas?]

The latter I would think. Section 3 of HASAWA and common law duty of care would apply regardless of the employment status of the person. If it can be demonstrated that you have control of a process or activity then those duties will apply to anyone affected by it.

Yes, and in a much broader sense. Much info. at gov.uk. Pragmatically, as others state, the master/servant argument applies. Concern regarding tax status may be a smokescreen by some.

With regard to Employers' Liability insurance, the HSE guidance is shown below. As has been mentioned above, the main factor is the level of control - not what the role is called or how the individuals are taxed / paid.

"Whether or not you need employers’ liability insurance for someone who works for you depends on the terms of your contract with them. This contract can be spoken, written or implied. It does not matter whether you usually call someone an employee or self-employed or what their tax status is. Whether you choose to call your contract a contract of employment or a contract for services is largely irrelevant. What matters is the real nature of your relationship with the people who work for you and the nature and degree of control that you have over the work they do."

More details at:-
http://www.hse.gov.uk/en...tion/status-specific.htm