Food wholesaler Booker has begun to restrict its supply of beer and cider due to the CO2 shortage across Europe and the UK.
The firm said it was capping cases of beer to 10 per customer and five cases of cider or soft drinks.
It is the latest business to announce issues with supplying the pub trade with beer, cider and carbonated soft drinks since the news of the CO2 shortage last week.
Booker said in a statement: "Due to the international shortage of CO2, we are experiencing some supply issues on soft drinks and beer.
"We are currently working hard with our suppliers to minimise the impact for our customers and cannot comment further at this stage."
It comes as reports claim JD Wetherspoon and pubco Ei have sites that have run out of some brands of beer. A spokesperson for Ei said it was working with suppliers to minimise disruption to publicans and sourcing alternatives, according to the BBC.
JDW said brands including John Smith's and Strongbow had run out for a few days, but that supplies were expected soon. Heineken has said its breweries are working at full capacity, 24 hours a day, to ensure shortages are minimised.
Trade magazine Gas World, which first reported on the issue, said the CO2 shortage was "worst supply situation to hit the European carbon dioxide (CO2) business in decades".
Supplies of kegged John Smith's Extra Smooth and Amstel have already been affected with Heineken saying it was working hard to resolve the issue as quickly as possible to avoid disruption.
Shortages of supplies of Pepsi and Britvic products including 7UP, Tango, Mountain Dew could occur by next week, according to reports. Coca-Cola has already "temporarily paused" production on some lines.
Brigid Simmonds, chief executive of the British Beer and Pub Association, said: "We have recommended our members to continue to liaise with their providers directly where they have concerns over supply, but are monitoring the situation carefully.
"We continue to engage with the government on the issue and call for their assistance; such as increasing storage capacity for CO2 in the UK, to ensure this does not happen again."
The British Soft Drinks Association has also commented, and said the shortage was still impacting a wide range of businesses across the food and drink sector.
The shortage has also impacted the food supply chain with concern specifically over pork and chicken slaughtering and processing – although alternative methods are being used to bypass the issue.