A couple have had three foster children removed from their care because they belong to the UK Independence Party.
Rotherham Borough Council said the children were "not indigenous white British" and that it had concerns about UKIP's stance on immigration.
It said it had to consider the "needs of the children longer term".
The unnamed couple told the Daily Telegraph social workers had accused them of belonging to a "racist party". UKIP said it was an appalling decision.
The couple, who have been approved foster parents for seven years, were eight weeks into the placement when they were approached by social workers about their membership of the party.
The wife told the Daily Telegraph: "I was dumbfounded. Then my question to both of them was, 'What has UKIP got to do with having the children removed?'
"Then one of them said, 'Well, UKIP have got racist policies.' The implication was that we were racist. [The social worker] said UKIP does not like European people and wants them all out of the country to be returned to their own countries."
The paper says the woman denied she was racist but the children were taken away by the end of the week.
She said the social worker told her: "We would not have placed these children with you had we known you were members of UKIP because it wouldn't have been the right cultural match."
The couple said they had been "stigmatised and slandered".
Rotherham Borough Council's Strategic Director of Children and Young People's Services, Joyce Thacker, told the BBC: "We always try to place children in a sensible cultural placement.
"These children are not UK children and we were not aware of the foster parents having strong political views. There are some strong views in the UKIP party and we have to think of the future of the children."
She said the issue related to the party's policies on immigration issues.
The council said there was no blanket ban on UKIP members being foster parents and that this couple would be allowed to foster other children in the future.
UKIP leader Nigel Farage condemned the decision and said the council had many questions to answer.
"They have to look at themselves in the mirror and ask who it is that is prejudiced? A normal couple who have fostered for seven years, or themselves who are blinded by political bias?
"Publicly they must make absolutely clear the decision-making process in this case, who was responsible for this decision and why."
The UKIP describes itself as a "Libertarian, non-racist party seeking Britain's withdrawal from the European Union".
It currently has 12 MEPs and 31 councillors, with three peers in the House of Lords.