A brand of crisps emblazoned with a caricature of Princess Anne has left a sour taste with Royal officials.
Creators say the snack is "blue-blooded" and "bracingly British"
The Horseradish and Sour Cream flavour delicacy is part of the new Crisps for Snobs range from Oxford-based manufacturer Jonathan Crisp.
But Buckingham Palace says the company has no right to decorate the packet with a cartoon of the Princess Royal, a former Olympic horsewoman.
The company describes the crisps as "blue-blooded" and "bracingly British."
A Royal spokesman told the BBC News website: "Buckingham Palace guidelines state that images of royals should not be used to promote commercial products.
"From time to time this is relaxed, during Jubilee years for example, when images of the Queen may be used to celebrate the occasion.
"Caricatures are a light-hearted matter, but if it is suggested to us that guidelines have been broken, we would look into that.
"Any correspondence we may have entered into is a private matter between the palace and the company."
'Acres of oomph'
Paul Saxby, the managing director of Jonathan Crisp, told the BBC News website: "Horseradish and sour cream is a very British flavour and we brought that to life as an equestrian lady.
"I had a very cordial conversation with the Buckingham Palace press office yesterday and they expressed the view that it could be interpreted as being Princess Anne.
"We are now reviewing the design, so the current packet could become a collectors' item.
"Some people even say the character with the cheesy grin on our Mature Cheddar and Red Onion flavour is Tony Blair.
"Others suggest the characters are drawn from Cluedo, or the Alec Guinness film Kind Hearts and Coronets.
"It is all meant to be very tongue in cheek and fun."
The company's blurb describes the Princess Anne-inspired snack as: "A bracingly British crisp with delightfully eccentric tastes.
"This blue-blooded flavour is straight out of the top drawer, raffish but impeccably groomed, tastefully turned out and packed with acres of oomph."
Other flavours in the Snobs range include Sea Salt and Black Pepper, described as "jolly privileged", and Sundried Tomato and Basil - "seen in all the right places".