The Royal British Legion has urged FIFA to reconsider their ban on England and Scotland's footballers wearing poppies.
Both countries are planning to defy football's international governing body by wearing black armbands bearing poppies for their World Cup Qualifier on Armistice Day, November 11.
FIFA has insisted their ruling - which prohibits teams from displaying political, religious or commercial symbols on their kit - would not be changed.
The UK charity for British armed forces has now written to FIFA to explain the symbolism behind the poppy and to stress that it has "no political, religious or commercial meaning".
RLB director general Charles Byrne wrote: "To the governing body of FIFA.
"The red poppy is a symbol of Remembrance and hope for a peaceful future. It has no political, religious or commercial meaning.
"This small red flower that grew on the devastated battlefields of the First World War is a solemn reminder of the cost of war and the price of peace. The red poppy is worn so that we never forget the commitment and sacrifices of the serving, never forget those who need help to live on through the consequences of war, and always remember our troubled world needs reconciliation and peace.
"Since 1921 the Legion has protected the red poppy from political or partisan misuse and ensured it remains a symbol that can be worn with pride by those of all ages, backgrounds, and political and religious beliefs.
"Many nations respect and honour the sacrifices of their Armed Forces and the red poppy is an international symbol worn around the world. Each year 1.5m poppies are sent to 50 countries worldwide, there are distinct red poppies worn in Canada, Australia and New Zealand for Remembrance, and in France they wear the bluet. We can see no reason why this simple symbol cannot be worn by players at international football matches should they choose to.
"The poppy represents sacrifices made in the defence of freedom, and so the decision to wear it must be a matter of personal choice. We would never insist upon it, as to do so would be contrary to the spirit of Remembrance and all that the poppy stands for.
"This year the Legion is asking the nation to rethink Remembrance when they wear their poppy, and recognise that all generations of our Armed Forces community, from the Second World War through to the present day, need our support. The poppy is as much to support the future of the living, as to honour the memory of the fallen and we thank the football associations of the home nations who have helped us carry this message to the millions of football fans watching their matches this Remembrance period.
"We ask you, FIFA, in the strongest terms that you rethink your approach to remembrance and the use of the poppy and permit players to honour the commitment and sacrifices of the Armed Forces."