A German politician has voiced her concern over marriage equality opening the door for polygamous or incestuous relationships.

Annegret Kramp-Karrenbauer, member of Angela Merkel’s Christian Democrat Party (CDU) and minister president of the federal state of Saarland, said the German government had to continue protecting the marriage between man and woman.

‘The question is whether we want to change some of our society’s fundamental definitions, and with potentially far reaching consequences. Until now, we have had a clear definition of marriage as being between a man and a woman,’ she said in an interview with newspaper SaarbrÃ¼cker Zeitung.

‘If we open this definition, to a permanent partnership of responsibility between two adults, we cannot rule out other demands: for example, marriage between close relatives or between more than two people.’

At present, 23 countries, as well as parts of Mexico, 37 US states and the District of Columbia, allow same-sex couples to marry; only a few of them, including France, Belgium and Luxembourg, allow incest between consenting adults.

The minister said there was no doubt about discrimination against LGBTI people having to stop, but she still opposed equal adoption rights for gay couples.

‘For years it has been said father and mother are the best constellation for a child’s development. We complain about children not having enough male role models in nursery and primary schools,’ she said.

‘It’s not clear to me how that should not affect their closest environment, where children’s characters are molded.

‘We cannot link this question to whether someone feels discriminated against or not – we can only link it to child welfare.’

According to the interview, the CDU is discussing equal marriage but opinions are widely spread; the minister said on a national level she did not consider the question of marriage to be a question of conscience, but a question of coalition agreements.