I think that, regrettably, many people are being 'driven into the arms' of the BNP by what is seen as (& often rightly) the Governments inept handling of the whole issue of Immigration/Asylum Seekers/Migrant Workers.
There are people that believe that in certain areas of London, 'Immigrants' (though its the case that many perceived as immigrants are actually British-born to foreign-born parents) are close to outnumbering ethnic Brits. The same situation is perceived (or claimed) up here in the North, though in London or up here, I don't think that except in small areas (a matter of a few streets together, for instance) do numbers in those areas achieve anything like parity of numbers, let alone dominant numbers of what the BNP would consider 'foreigners'. Maybe others can confirm this?
As usual, much of the blame for this skewed perception can be laid at the foot of the media. Particularly over Christmas, there was a slew of newspaper articles reporting that in such-&-such a place, traditional decorations were not being publicly displayed for fear of offending non-Christians. There had been instances of the same sort of thing re Guy Fawkes night, again jumped on by the press. I place the fuss over the Air Stewardess & her crucifix in the same category. In not one instance that I saw did the media place blame for all this nonsense where it belongs, at the feet of the 'Political Correctness' lobby, & thus, those who wish to have their prejudices reinforced use these instances as further ammunition against ethnic minorities.
As for Ms Clarke, well I agree with what seemingly everyone has said here, its not really relevant that a dancer holds such views, though doubtless the 'PC Brigade' will disagree, & we'll hear their disagreements in due course.