The anti-monarchy group Republic has warned schools that they may be breaking the law if they take part in a cooking contest to mark the Queen's diamond jubilee.
The "Cook for the Queen" contest, launched by the Duchess of Cornwall, is for 10 to 15-year-olds in all primary and secondary schools in the UK.
But Republic argues that involving children in celebrations of the monarchy without teaching them about republicanism as well is a breach of the Education Act.
The Westminster government said the rules were not designed to stop children taking part in national events.
The Duchess of Cornwall came up with the idea for the competition to encourage children to devise a new dish in the vein of coronation chicken. That recipe - cold chicken with a creamy curry sauce - was invented to mark the Queen's ascent to the throne in 1953.