The high point of Britain's summer has fallen somewhat flat after a shortage of food-grade carbon dioxide gas CO2 saw wholesalers introduce restrictions on bulk buying of drinks.

With the ongoing World Cup, the Wimbledon tennis championships just around the corner, and the country enjoying its hottest temperatures of the year so far, cold drinks are proving more popular than ever, but the supply chain of CO2 has encountered major problems.

The issue was first highlighted by Gasworld magazine, which said the shortage was being described as "the worst supply situation to hit the European carbon dioxide (CO2) business in decades", and Britain is particularly badly affected.

CO2 is the gas used to carbonize soft and alcoholic drinks, deliver drinks in bar pumps, and in the packaging of fresh meat and salads.

One of its major sources in Western Europe is ammonia plants, which are grown for the fertilizer industry.

Peak production time for fertilizer, however, is the winter, which means productivity is substantially reduced just at the time that demand for CO2 rises.

A combination of falling market prices and seasonal shutdowns of CO2 production facilities in mainland Europe has left the United Kingdom, which imports about one-third of its CO2, with just one functioning plant, causing supply fears and limits on purchases.

Even transportation is complicated. Gasworld reported that although there are supplies available in southern Europe, they can only be transported to northern Europe in specialist pressurized vehicles.

Food wholesaler Booker, owned by the Tesco supermarket chain, is rationing customer purchases to 10 cases of beer, and five of cider or soft drinks.

The British Beer and Pub Association, or BBPA, the industry body of brewers and around 20,000 UK pubs, told the BBC that the shortage was causing some stoppages in beer production, but did not name specific companies affected.

The BBPA also said it had reminded its members that only food-grade CO2 was acceptable for serving drinks, and to ensure they did not use any unofficial sources.

It is not just the drinks industry that has been affected by the shortage.

The British Poultry Council has warned that poultry processing plants could be badly hit, and Fiona Steiger, deputy director of the British Meat Processors Association, said the situation was getting "pretty tight for some people".