Businesses in Ireland have been warned that if they buy Christmas crackers sourced from the UK, they will have to add additional labelling to them before they can sell them, because of Brexit.

The label will have to include the importer's names, registered trade name or trademark and postal address.

If it is not possible to label each individual cracker, then the information can be added to the packaging or in a document accompanying them.

The requirement arises because since Brexit, the UK is now treated as a third country.

As a result, an EU directive governing the sale of pyrotechnics, including Christmas crackers, no longer applies to it.

Instead, importers of pyrotechnics that have been sourced from the UK, either because they were manufactured there or imported into there from another third country, must add information detailing their origin using a label or document.

"Only Christmas crackers which are in compliance with this EU Directive can be placed on the market in Ireland," said an information bulletin distributed by the Department of Justice to businesses here.

The change does not apply to crackers sourced from Northern Ireland because of the protocol.

Crackers placed on the market in the EU or the UK including Northern Ireland prior to 1 January when the Brexit transition period ended, may continue to be sold on the EU market until they reach their end-user date.

It is the latest example to emerge of a change to the trading rules governing a specific product arising from Brexit.