Marmalade sales surged last month as the nation paid its respects to the late Queen by leaving the breakfast staple as a tribute at memorial sites.

The unusual mark of condolence was inspired by a comedy sketch performed by Queen Elizabeth for the Platinum Jubilee celebrations earlier this year.

In the sketch, Paddington Bear joined her in Buckingham Palace for tea and marmalade sandwiches, his favourite food, which she later produced from her handbag herself.

In the wake of her death on September 8, so many people left marmalade sandwiches alongside floral tributes that the Royal Parks, the charity responsible for managing the spaces in London, issued a statement discouraging mourners from the practice.

Kantar, the consultancy firm, published new grocery market data yesterday showing that marmalade sales had risen by 18 per cent in September compared with weekly averages from earlier this year.

Fraser McKevitt, Kantar’s head of retail and consumer insight, commented: “One standout from the data this month was the surge in marmalade sales by 18 per cent as the nation paid its respects to the Queen.”

Marmalade was not the only product to experience a sales uplift in the days following the Queen’s death. Reports at the time noted that the aperitif Dubonnet — believed to be the Queen’s favourite tipple — sold out from supermarkets online as shoppers rushed to stock up ahead of the funeral.

It was not the first time this year that the Queen had boosted sales. Shoppers also splashed out during the Platinum Jubilee in June, spending a combined extra £87 million during the week of the festivities, according to Kantar.