England and Scotland players will wear black armbands bearing poppies in their World Cup qualifier at Wembley on November 11.
The English and Scottish Football Associations decided to go ahead with the Armistice Day tribute despite the FIFA general secretary Fatma Samoura's insistence that no exceptions would be made by the world governing body. The game's laws state that players' equipment should not carry any commercial, political or religious messages and FIFA is standing its ground, with Samoura warning Theresa May not to interfere after the Prime Minister called its stance "utterly outrageous".
The Football Association said it took its founding role on the International Football Association Board (IFAB), which sets the game's laws, "extremely seriously" but disagreed with FIFA's view that the poppy was political.
"The poppy is an important symbol of remembrance and we do not believe it represents a political, religious or commercial message, nor does it relate to any one historical event," it said. Soon after the FA's statement was published the Scottish FA confirmed its players would also wear armbands, as the two teams and Wales did during three November friendlies in 2011, that time with FIFA's permission.
Wales, who host Serbia in Cardiff on November 12, have yet to announce if they too will ignore FIFA.
The Home Nations had hoped to persuade Samoura, who is in London for an IFAB meeting on Thursday, at a dinner on Wednesday evening.
But in an interview with the BBC before that dinner, the former United Nations diplomat appeared to end any prospect of a settlement.
Referring to IFAB, which is comprised of the four British FAs and FIFA, Samoura said it "represents 211 member associations and each of them will be also ready to ask for similar exceptions".
The Senegalese official said she had already been approached by other FAs asking for their own one-off exemption but had said no because the laws must be applied "uniformly".
When asked if an exception could be made for an act of remembrance, Samoura said: "Britain is not the only country that has been suffering from the result of war.
"Syria is an example. My own continent has been torn by war for years. Why are we doing exceptions for just one country and not the rest of the world?"
FIFA's position has already provoked an angry response from the British media, politicians and veterans groups, with May weighing in during Prime Minister's Questions.
"I think the stance that has been taken by FIFA is utterly outrageous," she said.
"Our football players want to recognise and respect those who have given their lives for our safety and security. I think it is absolutely right that they should be able to do so."
And in a direct message to the Swiss-based federation, which has been plagued by corruption allegations, May said: "Before they start telling us what to do, they jolly well ought to sort their own house out."
The question now is whether England, Scotland or Wales, if they decide to snub FIFA, will be punished.
When asked if they would be sanctioned, Samoura said: "It is not really my ambition to punish anybody. They just have to recognise they are part of the rules of the game and they should be ready to face any kind of sanctions.
"They know better than me because they made the law."
She added that it would be up to the match commissioners - FIFA's representative at internationals - to make a complaint. A decision on punishment, which could be a points deduction, would be made later by a disciplinary panel.
When asked if she had a message for the Prime Minister, Samoura said: "No message to her. I would just ask anybody to refrain from political interference."
There are no such concerns for England's rugby union players, though, who will wear jerseys imprinted with poppies for their autumn series opener against South Africa at Twickenham on November 12.
And they will do so with World Rugby's permission.
Rugby Football Union chief executive Ian Ritchie said: "Poppies have always been an integral part of our situation, so the England team will be wearing it on the shirt.
"Why would you not have an act of remembrance? I think wearing a poppy is part of that."