They work in a job where they have to deal regularly with ethnic minorities, and explicitly supporting a party who is against the presence of ethnic minorities in Britain compromises their ability to do that in a neutral and effective way. At the very, very least it opens them up to accusations of bias that would make their jobs inefficient to the point of untenability; in worse cases, they might very well act in a genuinely biased way.
It's a very simple thing and has nothing to do with fascism or discrimination.
except you can be a complete racist, incompetant not get fired and NOT be a member of the BNP party so completely safe. Not all racists are BNP members, and not all BNP members/supporters are racist. They aren't saying lets fire the BNP members who are actively racist and/or giving worse treatment to minoritys and if they were saying that, why not say ALL nurse who are racist and/or giving worse treatment.
Not to mention people in this thread, and in england in general. I support almost no views of ANY of the main party groups, there are a couple of policies the conservatives have, a couple the lib dems and a couple the green have that I like. If i vote/support any one of those groups it DOESN'T mean I support their every decision, nor does it automatically mean I support any of their main campaign promises. I can catagorically say that IF I vote this time around it won't be due to any support whatsoever for the main idea's behind whatever party I voted for.
You can be a BNP member because they are pro british industry, against wasting money on benefits etc, etc, and completely and utterly disagree about their idea's on immigration, but you just like the other main political parties even less. You can support BNP and not be remotely racist or want immigrants out of the country.
Again, anything with a blanket statement of discrimination is that, its very obviously NOT taking it on a person by person statement, and its very obviously using a personal agenda/opinion on what THEY think BNP members think to institute policy, which is completely and utterly wrong on every level no matter how you try and justify it.
I'd happily see every single racist member of the BNP sent to an island to live alone with only whities, keep them and their hate away from everyone else, and they can be happy too. However, if I instituted a policy that to get it done, simply said every last BNP supporter had to be rounded up and shipped out I'd be indefensibly tarring a group of people with the same brush with no proof of who or what they are at all.
This is all ignoring the fact that due to security issues, and stolen BNP party lists people know who a lot of the members are, what about those racists, or non racists that people don't know are BNP members, its all a joke.
Fire those, who are incompetant, keep those that are good, should be that simple in every single job. Race, creed, ethos, ideology should play no part in deciding if you're good enough to work somewhere. If you're doing good work, you're good enough, if you're not, you're not.