When Geoff Bower, head of Woldgate school in Pocklington, north Yorkshire, was approached by McVities - the makers of Linda McCartney vegetarian meals - to run a free promotion, he was delighted.
"Most pupils are only interested in 'chips, chips, chips'," he said. "I saw this as a chance to offer something a bit different and healthy."
Moreover, every three veggie meals eaten earned pupils a pound;1 swimming-pool voucher.
But within days Mr Bower was deluged - by calls from farmers. "They thought we were indoctrinating the kids, waving veggie banners about and the like."
Then the local TV station ran a telephone poll on "vegetarian discrimination". Mr Bower says: "They even had a pig farmer interviewed on television who virtually accused me of bringing the UK farming industry to its knees."
Letters from parents followed, all of whom, according to the head, "had got the wrong idea and calmed down when they heard the simple truth".
He even had a phone call from a "furious" man at the Meat and Livestock Commission. The fuss finally subsided when the trial period ended: the school now has meat back on the menu.