JOHN Smith's bitter is the latest beer to have its alcohol content reduced by brewers.
Owner Heineken said its best-selling John Smith's Extra Smooth will be reduced from 3.6 percent ABV to 3.4 percent.
It falls under the new, lower tax rate on drinks below 3.5 percent.
Heineken also announced a 1.73 percent increase in the wholesale price of all its cask beers from Monday.
Pub landlords will likely have to pass the increase on to customers.
Heineken said the decision to make the bitter weaker was to promote healthy drinking.
Their spokesperson said: “We know consumers are increasingly choosing lower alcohol products as part of a balanced lifestyle.
“Recognizing this trend, we have decided to brew John Smith's Extra Smooth with a slightly lower alcohol content.
“Reducing the alcohol content of Britain's number 1 cask beer brand will remove millions of units of alcohol in the UK – in line with our long-held position to promote moderation.”
Last year, Carlsberg reduced its pilsner content to 3.4 percent, ahead of the government's alcohol tax changes.