The Royal British Legion has written an open letter to Fifa urging it to lift its ban on the England and Scotland national football teams wearing the poppy.
The football associations of both nations have vowed to defy the ban by world football's governing body, saying players will wear poppies on black armbands during their Armistice Day World Cup qualifier at Wembley.
Fifa has insisted that the laws of the game, which prohibit political messages from players' kit, mean poppies cannot be worn at the November 11 fixture.
But in an open letter to Fifa, RBL director general Charles Byrne said: "The red poppy is a symbol of remembrance and hope for a peaceful future. It has no political, religious or commercial meaning.
"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.
"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."
The move came as Fifa said it was opening disciplinary proceedings against the Football Association of Ireland (FAI) after the team's shirts in a friendly against Switzerland in March bore a symbol representing the 100th anniversary of the Easter Rising.