The Post office has said that statements that people should avoid using red envelopes this Christmas are untrue.

A spokesman said: “As the universal service provider, Royal Mail is proud to deliver the Christmas post for consumers and businesses. Our Intelligent Letter Sorting Machines can process up to 50,000 items an hour.

"Anything the machines are unable to read are almost instantaneously passed through to our data centre where our team of ‘address detectives’ identify the correct address. There is no impact on the delivery timescale for the customer.

"Customers are welcome to use any form of envelope or ink for their Christmas cards. The only advice we always offer - is to always use the postcode.”

The Royal Mail has recommended a series of last posting dates to ensure people get their cards in time for Christmas – second class is December 18, first class December 20 and special delivery, December 23.