There is a school of thought at the moment that as part of the fight against drugs, every single employee should be drug tested at their place of work. This proposition seems to have gained at least some popular support, although as far as I can tell no politician is pushing for this yet. Leaving aside any possible breach of human rights and invasion of privacy, which is not to be taken lightly, this seems to me to be an ill-considered proposal which would have deeply damaging social implications.
Of course, the idea is that employees who take drugs will reconsider doing so, due to the possibility of loosing their job through being tested positive at work. This may well be the case for some occasional drug takers, but what happens to those, for example, who are regular cannabis smokers and who are not willing to forgo one of their pleasures? Estimates of adult cannabis usage in the UK put the figures anywhere between 6% - 9% of the population. Even if we take a very conservative estimate, that's well over 3 million cannabis users of working age. That's potentially 3 million people, many of whom are good and productive workers, now unemployed and claiming benefits. And the perverse thing is that takers of harder drugs, such as ecstasy and cocaine, have a better chance of keeping their jobs as their drugs of choice take a much shorter period of time to work their way out of the body.
What a scandal this would lead to if passed in law. Employers would loose many of their best workers, those who lost their job would find it extremely difficult to find new employment, and the drain on our already very tight public funds would be immense. I'm not condoning anyone going into work under the influence of any drug, including alcohol, but as long as an employee is doing their job to a satisfactory level, is it really of any concern to the employer what they do outside of work?