British politicians lined up on Saturday to denounce a decision to take three ethnic minority children away from their foster parents because the couple support the anti-immigration UK Independence Party.

The couple from Yorkshire said they had been fostering children for seven years but have been told by social workers that they were not suitable because of UKIP's calls for curbs on immigration to Britain.

Education Secretary Michael Gove said the decision was "indefensible" and opposition Labour leader Ed Miliband, whose party runs the local authority involved, called for an urgent investigation into the "very disturbing" claims.

UKIP leader Nigel Farage, a member of the European Parliament, said the situation was "appalling" and "disgraceful". He accused the council of bigotry, insisting that decisions on foster care should be "colour-blind".

Following the outcry, Rotherham Metropolitan Borough Council announced that it would launch an investigation into the actions of its staff.

The couple involved told the Daily Telegraph newspaper they had been "stigmatised and slandered" by the removal of the baby girl, boy and older girl they had been caring for for eight weeks.

The decision came after two officials visited to question them about their membership of UKIP, Britain's fourth-biggest party which campaigns for an end to Britain's membership of the European Union and a freeze on immigration.

The woman, a qualified nursery nurse, 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."

She asked what UKIP had to do with the decision, "then one of them said, 'Well, UKIP have got racist policies'. The implication was that we were racist."

The identity of the couple, who are in their 50s, has been kept secret to protect the children.

Education Secretary Gove condemned Rotherham council for making "the wrong decision in the wrong way for the wrong reasons" and said he would be looking into what happened.

"Rotherham's reasons for denying this family the chance to foster are indefensible. The ideology behind their decision is actively harmful to children," he said, adding that it sent a "dreadful signal" to other foster parents.

Labour leader Miliband added: "Being a member of UKIP should not be a bar to adopting or fostering children."

Rotherham council's director of children's services, Joyce Thacker, told BBC radio the three ethnic minority children had been placed with the couple as an emergency and it was never meant to be a long-term arrangement.

"The children have been in care proceedings before and the judge had previously criticised us for not looking after the children's cultural and ethnic needs, and we have had to really take that into consideration," she said.

Thacker added: "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."

UKIP started life on the fringes of politics but a recent ICM poll suggests it now has the support of seven percent of voters. It has 12 MEPs but has yet to win a seat in the House of Commons.