Crumpets have become the latest casualty of the carbon dioxide (CO2) shortage hitting the UK's food and drink industry - with retailers warning that stocks may dwindle this weekend.

Producer Warburtons said it is working 'really hard' to keep products on shelves, but admitted it is making 'nowhere near' its usual amount of the British staple.

Just one of its plants – at Eastwood in Nottinghamshire – has been operating normally, it said. Two others – in Enfield, north London, and Burnley, Lancashire – are not producing any goods, while its Stockton-on-Tees branch has received a small supply of CO2 after being offline for days.

However, the East of England Co-op has moved to reassure customers planning to shop over the next few days.

A spokesman said the retailer was 'not expecting to see disruption to stock levels at our stores' but added that is was monitoring the situation closely with its suppliers.

The British Retail Consortium (BRC) said CO2 supply issues remained and companies were working hard to source alternative gas stocks.

'We are aware of specific pressures in some areas such as carbonated soft drinks, beer, British chicken and British pork but the majority of food products are unaffected and retailers do not anticipate food shortages. However, it is likely that the mix of products available may be affected,' said a spokesman.

Ian Wright, chief executive of the Food and Drink Federation (FDF), said the group was still seeking answers from its discussions with government.

'There is a serious concern that consumers may face a limited choice of food and drink on supermarket shelves if a normal supply of CO2 is not restored as quickly as possible,' he said.

The shortage has already affected beer and fizzy drinks producers, while meat processors will also feel the impact, as the gas is used to package meat to extend its shelf life.

READ MORE: CO2 shortage could become a 'major crisis' for meat supplies, says East Anglian poultry producerThe shortages are understood to have been caused by a longer than usual break in production of ammonia, one of the key sources of food grade CO2 in Europe.

Trade journal Gas World said the shortage had been described as the 'worst supply situation to hit the European carbon dioxide (CO2) business in decades'.

It comes as some pub chains reported they had temporarily run out or were short of John Smith's, Strongbow, Amstel and Birra Moretti as disruption to supplies of CO2 began to take effect at the bar.

The British Beer and Pub Association (BBPA) said stocks of the gas remained low but brewers were 'working their socks' off to ensure the beer continued to flow.

READ MORE: Norwich pubs will 'call in favours' to ensure beer keeps flowing as CO2 shortage bites

How are pubs faring?

The beer is still flowing at pubs in Norfolk – though many have had to swap new drinks in depending on what is available.

With the June heatwave continuing and spirits high on the back of England's World Cup run, landlords have been stocking up on substitutes to keep cellars full for the coming weeks.

Phil Cutter, landlord at the Murderers in Norwich, said he had swapped Stella 4 in for Amstel, production of which has been hit by the CO2 shortage.

'One of the joys of being a free house is we can choose what we buy in,' he said. 'When you've got the World Cup and a summer like we have, you can't afford to be reliant on two or three beers. You have to keep volumes up and in stock.

'This has probably come at the worst time for the pub industry, because we need a decent supply. What you don't want is to get to the week of the World Cup final and find you've got no beer.'