The regulator said that despite “generally working well” it is concerned about Royal Mail’s efficiency performance.

In other news, Royal Mail has warned customers to get their Christmas post sorted out as early as possible, to ensure it reaches friends and family in time.

Christmas is the busiest time of year and Royal Mail has recruited 20,000 workers to ensure Christmas cards and parcels are delivered.

Royal Mail said: “Allow plenty of time for posting. Please post items and gifts for Christmas early, particularly for International deliveries. Ongoing Covid restrictions, reduced air and freight capacity, high volumes and winter weather conditions are all impacting transportation and local delivery across the globe.”