The rivalry between Devon and Cornwall over the correct order of cream and jam on a scone is one of the country’s fiercest disputes, and locals are expected to know where their side stands.

A National Trust property in Cornwall therefore prompted understandable outrage after it advertised cream teas for Mother’s Day - with a photograph showing the cream being spread before the jam.

The advert, from Lanhydrock House and Garden, has been called “unacceptable”, “shocking” and “disgusting”, with some Cornish people threatening to cancel their memberships.

The scone shown in the advert has cream spread over each half, with jam spooned on top.

The traditional Cornish cream tea, however, is supposed to have the cream on top of the jam.

Facebook users were unhappy with the error, which the property blamed on a member of staff.

A statement said: "We'd like to sincerely apologise for any offence caused by a recent scone-shot shown on the page.

''The member of staff responsible has been reprimanded and marched back over the Tamar.

"We'd like to reassure our Cornish community that our catering team would never make such a heinous mistake and that our jam and cream are usually served in little pots so the order of their application is not subject to such appalling error. Rest assured, your mothers are safe here."