A head teacher said he was forced into his school’s kitchen due to ongoing problems with a hot meal service provided by a private company.

Malmesbury School’s head teacher Brett Jouny said G4S had been unable to supply “the right number” of catering staff for weeks and the issues had threatened the school’s Christmas dinner, which ultimately went ahead.

He said in addition to his normal duties, he had been serving burgers in the school cafeteria “because the number of staff available has been so poor”.

G4S refuted the claims and said it had “delivered a full lunch service” with the exception of one day in early-December.

But Mr Jouny said that over a period of two weeks G4S, which supplies catering at the school, had delivered a service that ranged from “a very, very sparse offering to normal”.

He said it was only after “a lot of shouting and a lot of being very grumpy” that the Christmas dinner went ahead on Wednesday with additional agency staff and an external chef.

Pupils said the lack of hot meals was impacting their school experience.

One said he “had to go off to the shops during my lunchtime” because there was no food available, while another girl said the issues had been affecting her concentration in class.

Councillor Jon Hubbard, cabinet member for education and skills, said Wiltshire Council was liaising with the school and G4S. He said the authority’s priority was to ensure pupils receive a “quality catering service”.