The Amalgamation of Official Northern Ireland Supporters Clubs (NISC) last night voiced its opposition to a UK Olympic football team.
The organisation teamed up with counterparts in England, Scotland and Wales to reject the proposal.
The Official Supporters Groups representing all of the home nations' teams yesterday released a joint statement calling for the idea to be scrapped.
Spokesman Gary McAllister said: " We welcome confirmation that the IFA has decided to withhold its support for a UK football team at the 2012 Olympic Games. The Amalgamation of Official NISCs has expressed some reservation about the concept of a UK team and the potential threat to the continued participation of the four home nations on an individual basis in future World Cup and European Championship competitions.
"Indeed, the head of the Concacaf (Caribbean and North/Central American) federation and Fifa Vice-President, Jack Warner, is on record as having lobbied for the abolishment of an automatic Fifa Vice-Presidency for the British Associations, which should surely serve as a warning that there are those who could well seek an end to the entitlement of the four home nations to compete seperately in international competition.
"Without assurances that the four British Associations will continue to have the right to compete as separate entities in the World Cup and European Championships, then a 'Team UK' in the Olympic football tournament is a complete non-starter."