Carmarthenshire council has announced that it will be investing pound;110 million in a new education programme, designed to ensure that all pupils have access to modern school buildings and facilities.
The aim is to create community schools, open from early morning until late evening. These will offer family support services, health care and adult education programmes on a single site.
To meet this goal, one new secondary and 19 new primaries will be built.
But, as a result, around a quarter of Carmarthenshire's 133 existing primaries will close.
David Davies, Welsh Assembly Conservative education spokesperson, believes this ignores the wishes of parents and children.
He said: "It's terrible news. People don't realise how important it is for parents that their children are educated locally. They don't want to be packing four-year-olds off on long school bus journeys."
At present, 38 of the county's primaries use mobile classrooms, and 14 have no indoor toilets. But Mr Davies does not believe closure is the best way to tackle such problems. "Small schools are important for bringing parents together," he said.
Kay Hart, head of seven-pupil Trapp primary, in Llandeilo, which is likely to close under the new plan, agrees.
She said: "There's nothing else in our village except for the pub. The local character will be gone once the school closes.
"Small schools offer a real academic advantage for children. It will be difficult for them to receive the same individual attention in a larger class."
In the past 10 years, the Assembly has approved the closure of 34 schools.
Twelve of these have been in Carmarthenshire. But Beth Leyshon, head of Ysgol Yr Ynys, in Llanelli, welcomes the amalgamation of her school into a new, 210-pupil primary.
"We have old buildings with damp walls, an outside canteen and no disabled access," she said. "Now the children will have a nice new facility which can be used by the community as well."
Carmarthenshire council says this is why it has developed its new proposals.
Vanessa Walters, of the education department, said: "Many existing schools are in Victorian buildings, serving communities that have moved on. We're helping schools to regenerate and sustain themselves for the future."