This is true, but there is much evidence that the BNP literally could not organise a pissing contest if you gave them a wall and a free bar.
According to some reports I heard at the election times, their vote actually FELL in areas they had had previous influence because as a one-policy party they cannot cope with multiple responsibilities effectively and many of those who had voted for them in the past wouldn't do so again. They prospered a great deal through apathy on the part of voters who were too disenchanted with voting to support anyone.