BRUSSELS - The Belgian royal family on Saturday rapped Burger King over an online advertising campaign suggesting a new "king" for the European nation.

The offending advert, found on the whoistheking.be website in French and Dutch, asks users to pick between "King Philippe" on the left and "Burger King" on the right.

Those who choose Philippe -- represented by a cartoon image that doesn't seem to resemble the real monarch -- are then asked: "Are you sure you want to elect King Philippe? He won't be the one to cook your fries".

But the Belgian royal family was not amused.

"We disapprove of this approach," royal spokesman Pierre Emmanuel de Bauw told AFP, saying the monarchy had contacted the burger chain over the ad.

"The use of the King's image is subject to authorization," he said.

"In this particular case, we received no requests. Since it is for commercial purposes, we would not have given our authorization."

Burger King's majority shareholder the Bertrand group bought French fast-food rival Quick in 2015 and has steadily re-branded Quick outlets in France.

But the deal maintained the Quick brand in Belgium, Luxembourg and outside of Europe, which is now being partially phased out with Burger King set to open its first Belgian outlet in June in the northern port city of Antwerp.