A five-year-old boy was given bread and water for lunch after the school refused to accept a 'late' dinner money payment.
Callum Slater, a pupil at Longmoor Community Primary School in Walton, Liverpool, usually goes to the school canteen each day for a tuna and cheese wrap and a pick and mix salad from the salad bar.
But Callum was made to eat an alternative lunch outside his headteacher's office after his mum Lesley tried to pay his £9 dinner money five hours 'too late'.
The school asks parents to pay money for the forthcoming week's meals by the Friday before.
But when Lesley tried to pay the amount at the end of the day, instead of in the morning, the school refused to accept it and Callum was stopped from eating in the school canteen the following week - despite initial assurances he'd be allowed.
Callum's grandmother Sheila told the Liverpool Echo that her grandson was given a bread roll and water for his lunch.
Sheila, 68, from Aintree, Liverpool, said: "They gave him a brown barmcake and a glass of water. Callum was so upset and he was saying 'what have I done?'
"When we took him to school the next day he kept saying 'have I got to sit outside the headteacher's room?'
"He's only five so he's not old enough to understand. He didn't understand why he couldn't sit with his best friend like he normally does."
The school has now apologised for any upset caused.
A spokesman said: "Pupils whose parents have forgotten to pay for school dinner are given a more basic packed lunch made up of a sandwich, a drink and a piece of fruit.
"To avoid embarrassment, pupils in this situation have their lunch away from other children.
"However, in this specific instance, due to a misunderstanding by a supply teacher, the child had the same lunch as every other pupil that day - a baguette, drink and a dessert.
"We have apologised to the parent and the child for any upset and confusion caused and taken steps to make sure the system for payment is communicated consistently in future."