There is more to this story than meets the eye.
Not that it should matter, but the assumption that the foster children would be classed as "european white children" seems false.
From the BBC, the foster kids were classed as "not indigenous white british", which implies a differently coloured skin, and the Telegraph were even clearer in one paragraph;
"They took on the three children — a baby girl, a boy and an older girl, who were all from an ethnic minority and a troubled family background — in September in an emergency placement."
http://www.telegraph.co.uk/news/politics/9700001/Foster-parents-stigmatised-and-slandered-for-being-members-of-Ukip.html
On the face of it, this is a spectacularly stupid decision by the social services. The couple have been fostering for 7 years, the children were described in the article as thriving, and the couple themselves with a background in caring for the disabled and nursing amply qualified. To remove children of a troubled family background from what seems a stable and loving fostering environment on the basis of an anonymous phone call tip off and support for a mainstream political party is absurd.
It will be interesting to see the outcome of this case, and whether more details emerge, but if this was some sort of politically motivated decision in furtherance of a left wing agenda, as some commentators perceive it, then whichever genius that thought it up needs to go back to school - how anyone could imagine that this would be seen as a positive boost to left wing support must be barking....