An "aggressive" beer sold under the name Punk IPA faces being banned after a ruling that it would promote irresponsible drinking.
The drink and two others made by BrewDog in Fraserburgh, Hop Rocker and Rip Tide, were found to have breached marketing rules in a provisional decision by the Portman Group, a self-regulating industry body.
It decided Rip Tide's description as a "twisted merciless stout" would be associated with antisocial behaviour, while the claim that Hop Rocker was a "nourishing foodstuff" and that "magic is still there to be extracted" implied that it would enhance physical and mental capabilities.
BrewDog, which was set up 18 months ago by two former law students, reacted angrily to the decision, saying it threatened to put the firm, which sells to Tesco, Asda, Sainsbury's and Oddbins among others, out of business. The company is given the chance to respond before a final ruling.
James Watt, co-founder of BrewDog with Martin Dickie, denied the advertising would encourage irresponsible behaviour. The label on Punk IPA, the main seller of the three, says "this is an aggressive beer, we don't care if you don't like it", which Mr Watt said highlighted the contrast in taste with light lagers.
"Our branding, our packaging, is a little bit edgy. The word 'aggressive' is used because of the biting bitterness in it. It's a heavily hopped beer. It's not something you can drink a lot of," he said.
"We could [change the label] but should we be pushed into changing our approach by our competitors? I think what they [the Portman Group] are doing flies in the face of anti-competition laws."
He said irresponsible drinking was more likely to occur as a result of strong lager produced by the major brewers being sold for a third of the price of his beer.
The Portman Group has also made a provisional ruling against Skull Splitter, a beer produced for 20 years by the Orkney Brewery and named after Thorfinn Hausakluif, the seventh Viking earl of Orkney, who had that nickname. It was decided the phrase was associated with violence and also could be a reference to its effect on the drinker's head.