A British-Asian peer has been accused of bigotry after she claimed that marriages between first cousins in Pakistani communities were leading to “absolutely appalling” disabilities among children.

The crossbencher Baroness Flather, who has described herself as a Hindu atheist, called for couples intending to marry to be required to take a DNA test to check they are not cousins.

Lady Flather, the first female Asian peer, told the Lords during a debate on ethnic minorities: “There are a lot of first-cousin marriages in certain communities, particularly among Pakistanis who come from the Pakistani Kashmir area.

“We know so much about DNA now, but there is so much disability among the children, which is absolutely appalling. You go to any such family and there will be four or five children, at least one or two of whom will have some disability. That is absolutely unacceptable, and if we cannot do anything about it, is it fair to the children?”

The 81-year-old peer, who was born in the Pakistani city of Lahore when it was still part of India, said: “Never mind the parents – it is not fair to the children that they should be allowed to become disabled because of a social practice.

“It is a social practice which does not belong in today’s age, when we know so much about DNA. There should at least be some rule which says that you must have a DNA examination before your marriage can be registered.”

Lady Flather also said the halal method of preparing meat should be banned. “Why should we allow anybody who comes to this country voluntarily to do that? It is not right,” she said.

The baroness was rebuked by the Conservative peer, Lord Sheikh, who said parts of her speech were “unfair and irrelevant” and “will not help community cohesion in this country”.

The Muslim Council of Britain said she had “a bee in her bonnet about British Muslims generally and those of Asian heritage in particular”.

It said: “Her consistent bigotry has unfortunately forfeited the right to be taken seriously.”