We’ve been told we are anti-Welsh bigots and even fascists,” says Alice Morgan in her soft Welsh accent. The comments she is talking about began when she and other parents raised objections to a plan to turn their primary school in the village of Llangennech into one that teaches only in Welsh. They are worried that some children used to being taught in English won’t cope.

One mother said she was now too frightened to walk down to the Co-op in the village to buy a loaf of bread. “It’s got that bad. Perhaps I’m being paranoid but I’m really scared at the moment. I’m not sure it’s good for the reputation of the Welsh language.”

While a Labour councillor described the move as a form of segregation or apartheid, some supporters of it have said that those who didn’t want to live in a Welsh-speaking village could always move out. The decision, voted through in January by Carmarthenshire council, will mean Llangennech school will join 479 others – just under a third (31.9%) of all schools in Wales – that teach exclusively in Welsh.

The change will come into operation for reception pupils in September and has delighted those who believe it will help revive the declining fortunes of the Welsh language. But opponents say it could damage the education of children whose first language is English and will force some parents to send their children outside the village or county for their education.

Morgan – who asked that her real name not be used to protect her family – has three primary-age children. Until now, villagers have had a choice about whether their children go into the Welsh or the English stream in school. Her eldest son started at Llangennech in the Welsh stream, but had difficulties. “He struggled tremendously for two years,” she says. “He was depressed and unhappy, vomiting before school, and he fell behind. Although we speak Welsh at home I think it was the fact that no English was used whatsoever that made him feel overwhelmed.” Things improved when he was able to move into the English stream. “He was a changed little boy.”