Pub chain Wetherspoon has revealed a 3.2 per cent decrease in like-for-like sales in the run-up to Christmas.
The firm, which runs 684 pubs across the UK, says the 11 weeks up to January 13th saw a marked downturn.
Despite strong customer spending on food, real ale and coffee, reduced sales of the chain's staple beverage, lager, contributed to the decrease.
The smoking ban, which came into force last July in England, has also had an impact on the pub's figures, the chain says.
When taking a broader look, the supermarket says that in the 24 weeks to January 13th like-for-like sales were down two per cent and overall company sales were up 0.4 per cent.
As part of what it calls a "cautious" outlook for 2008, Wetherspoon says it now only expects to open 25 new pubs during the current financial year, of which ten have already been opened. This is fewer than anticipated.
"In recent statements, we and other pub companies have emphasised an element of uncertainty and caution resulting from the smoking bans introduced in England, Wales and Northern Ireland in 2007," the firm said.
"We continue to remain cautious regarding the outlook for this financial year. We are confident that a non-smoking environment will result in growth in both bar and food categories in the medium and long term."
Following its results, and amid uncertain times on the stock exchange in general, Wetherspoon shares were down slightly to 291p just after 10:00 GMT.