World football's governing body has virtually guaranteed the future of England, Northern Ireland, Scotland and Wales as independent associations. The home nations' rights have been written into Fifa's statutes for the first time at the organisation's extraordinary congress of all 204 associations in Doha, Qatar.
It would require a 75% majority of all Fifa's associations to change the statutes in the future.
"The home nations' position is safer now than it has ever been, and that has been reinforced by the fact that Great Britain's continuing vice-presidency of Fifa has also been written into the statutes," said Football Association of Wales Secretary David Collins in Doha.
"It is the first time the position of the four associations has been enshrined in Fifa statutes.
"We have heard a number of times of the possibility of combining to form a Great British association, but now the position is clear."
The new statutes will come into force on 1 January, 2004.
Fifa president Sepp Blatter, whose term in office was extended by another year to 2007 at the Qatar congress, has previously spoken about the possibility of forming a Great Britain team as part of London's bid for the 2012 Olympics.
He stressed, though, that such a move would be a one-off and would not affect the long-term futures of the individual associations.