Karen Cowan’s 11-year-old daughter Michaela uses the bus.
The 44-year-old said: “I’m seriously disappointed. The future of the school has been put in jeopardy. I think this is their way of trying to close the school.”
The letter also told parents that they would need to make their own transport arrangements.
Emma Jahn’s six-year-old daughter Jennifer goes to the school and her four-year-old daughter Emily was due to start in August. She said: “I’m very shocked by what’s happened.
“I went to Shawhead Primary myself and if I had to move my daughter it will cause disruption to her learning.”
Director of education Colin Grant said: “Parents in Terregles who have chosen to send their child to Shawhead Primary School have received free transport to the school on a grace and favour basis, due to the availability of bus transport at a minimal cost.
“Unfortunately the council now has to withdraw this as the number of children entitled to free transport has dropped and a bus is no longer required to transport them.”