Sell-by dates on packaged food will be reduced as a result of a nationwide shortage of carbon dioxide, the Telegraph has learnt.

The gas is used in the vacuum-packing process for meat, poultry, cheese, salads and ready meals to preserve them. Industry insiders say that to avoid such products running out, they will have to be given a shorter shelf life.

In order to eke out existing supplies of CO2, factories are likely to dilute it with other gases, which will affect the length of time they can be left on shelves before being consumed.

As a result, shoppers are being warned to pay close attention to what they buy, with consumer groups saying they could be “caught out” by the shorter dates.

Supplies of beer and fizzy drinks could also run low but shoppers have been told there is no need to panic-buy despite what has been described as the "worst C02 supply situation in Europe for decades".

One industry source told The Telegraph: “In the short term, we are likely to see the shortening of use-by dates on anything that is vacuum-packed as opposed to lack of supply of products - that is the more pressing concern.”

James Daley of the consumer group Fairer Finance said: “It is important retailers are really clear with customers about the change. If someone is used to buying something regularly, and the date is usually a standard time away, then they will not necessarily be checking the use by date.