The Royal British Legion has written to Fifa, urging it to lift its poppy ban, saying the symbol “has no political, religious or commercial meaning”.
England and Scotland’s players will defy a ban on wearing poppies when the teams meet on Armistice Day.
“We ask you, Fifa, in the strongest terms, that you rethink your approach to remembrance and the use of the poppy,” the armed forces charity said.
“The poppy is a symbol of remembrance and hope for a peaceful future.”
World football’s governing body prohibits political, religious or commercial messages on shirts.
England play Scotland at Wembley on 11 November in a World Cup qualifier.
English FA chief executive Martin Glenn says players from both sides will wear black armbands carrying the poppy symbol – traditionally used to remember those who died during World War One – “as a point of principle”.
Both the England and Scottish FAs say they are continuing to negotiate with Fifa and are hopeful of finding an amicable solution.
In an open letter to Fifa, Royal British Legion 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.
“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.
“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.”
The letter was published on the day Fifa said it was opening disciplinary proceedings against the Football Association of Ireland after it became aware that the Republic’s football team had worn shirts in a match in March that had featured a logo marking the centenary of the Easter Rising.
What do the rules say?
The International Football Association Board (Ifab) – made up of the four British FAs and Fifa – is responsible for formulating the laws of the game, which are then upheld by Fifa.
The laws cover everything from the field of play to the equipment used and how the result of a game is determined.
A section of law four, which deals specifically with players’ equipment, reads: “Equipment must not have any political, religious or personal slogans, statements or images.
“Players must not reveal undergarments that show political, religious, personal slogans, statements or images, or advertising other than the manufacturer’s logo.
“For any infringement the player and/or the team will be sanctioned by the competition organiser, national football association or to be justified by Fifa.”
It does not specify what the sanctions are for breaching those rules.