Mind you, our right-wing MPs are spouting some ridiculous rhetoric on the subject:
I don’t smoke, so I like smoke-free environments. But I have watched the assault on smokers with a growing unease... My foreboding is based on a sense that discriminating against a group of fellow citizens just because they smoke, is morally wrong. Surely, it is no different to discriminating against people because of their race, gender, sexuality, or religion? Isn’t this the first step onto the slippery slide of apartheid?
Um, no. The individuals are still welcome everywhere, it's just their tobacco that isn't. Having said that, this response is somewhat reminiscent of that sometimes given by gay marriage opponents to rebut accusations of discrimination, you know the one: "Everyone is allowed to get married -- so long as they marry someone of the opposite sex." Even 'universal' laws can be discriminatory, if they unfairly impede a particular group's pursuit of the good life. If we want to claim that denying everybody the liberty to marry a partner of the same sex is discriminatory, then doesn't consistency require that we say the same of denying everybody the liberty to smoke in bars?
Perhaps we should concede this, but add that such "discrimination" is justified in the latter case only. Same-sex marriage harms no-one, so there's no reason to ban it. Smoking in enclosed places does harm other people, so there is at least some reason to ban it.
Is it a good enough reason? The free market argument against it seems quite strong. No-one is being forced to visit or work in a place which allows smoking. If the jobs really are hazardous, then workers' wages should reflect this, and by signing up for the job, they consent to the risks. So why intervene? Perhaps it makes for a nicer environment for the rest of us, but if it's really that big an improvement then owners have an incentive to institute their own private smoking bans.
Now, in reality the free market often fails. Perhaps that has happened in this case, in which case government intervention would be justified in order to bring about the optimal result. But proponents of the ban must explain: where, exactly, is the market failure? Have bar owners been mistaken about what would best satisfy their customers? Have the workers been misinformed about the job risks, or not adequately compensated for it? Perhaps some lack any reasonable alternatives and thus are effectively forced into accepting the hazards against their will? Some explanation is required, anyway...