The British Beer & Pub Association (BBPA) has been left red-faced after a ruling forced it to scrap its advert suggesting a third of a price of a pint goes to the government.
The Advertising Standards Authority (ASA) upheld a complaint from a CAMRA member about the ad - which has been at the centre of the BBPA's Axe the Beer Tax campaign.
The ruling says the ad must not appear again "in its current form".
The complainant felt the ad, which appeared in CAMRA's What's Brewing magazine, gave the impression 33 per cent of the price of a pint "in the pub" was tax applied by the government.
However, the BBPA has admitted the 33 per cent figure relates to duty on beer sold in pubs - and the off-trade. It says duty plus VAT on pints in the pub amounts to 28 per cent of the price but that the total tax on every pint in the on and off-trade is actually 39 per cent, when employment taxes are also taken into account.
The ASA said because the ad showed a pint glass and it appeared in What's Brewing it "reinforced" the idea that it related purely to beer sold in pubs.
The ASA said: "We noted beer was generally sold more cheaply in supermarkets and shops than in pubs and bars and considered that by including off-trade sales, the ad gave the impression that the proportion of the cost of a pint of beer in the pub paid to the government was more than it was."
But the BBPA argued the ASA has adopted a "limited interpretation" of the advert and what constitutes tax.
Acting chief executive David Long said: "Far from intending to mislead people, this advert sought to bring honesty and openness to the debate on the amount of taxes people really pay.
"As only one person complained about this advert, it seems everyone else understood exactly what we were saying."
"Taken together, the total tax paid on every pint is in fact 39 per cent, and the BBPA will certainly make this clear in any future advert we do."
CAMRA, which has also been involved with the Axe the Beer Tax campaign, has also hit out at the ruling.
"We are bemused at the ASA's decision," said Jonathan Mail, CAMRA's head of policy and public affairs.
"The ASA's assessment seems to suggest that pint glasses are not used by people drinking at home and that our campaign should communicate the exact tax paid on each of over 2,000 different beers instead of using an average.
"Ironically the statement that the Chancellor takes 33 per cent of the price of a pint is an underestimate as it is based only on duty and VAT and ignores other taxes, such as business rates and employment taxes, indirectly paid for by the beer drinker.
"We question whether it is appropriate for the ASA to intervene in a legitimate political campaign aimed at exposing the excessive tax burden imposed on beer drinkers."