Marks and Spencer is warning customers not to eat some of its soup as it may contain “small pieces of metal”.

The affected soup is being recalled by the supermarket, with the Food Standards Agency (FSA) issuing a “do not eat” warning.

The soup being recalled is the M & S Smooth Butternut Squash Soup with a use by date of October 6.

A spokesman for the FSA said: “Marks & Spencer is recalling the above product. Point of sale notices will be displayed in all retail stores that are selling this product.

“These notices explain to customers why the product is being recalled and tell them what to do if they have bought the product.

“If you have bought any of the above product do not eat it. Instead, return it to your nearest store for a full refund.

“For more information contact Marks & Spencer on 03330148555.”

An M&S spokesman added: “Customer safety is of paramount importance to Marks & Spencer, and we take all issues regarding the production of our foods extremely seriously.

“Please do not consumer this product. Any customers in possession of this product can return it to their nearest store where a full refund will be given.

“We apologise to our customers for any inconvenience caused.”

What is a product recall?

If there is a problem with a food product that means it should not be sold, then it might be 'withdrawn' (taken off the shelves) or 'recalled' (when customers are asked to return the product).

The FSA issues Product Withdrawal Information Notices and Product Recall Information Notices to let consumers and local authorities know about problems associated with food.

In some cases, a 'Food Alert for Action' is issued.

This provides local authorities with details of specific actions to be taken on behalf of consumers.