Scotland's international football bosses are against the move
Tory leader David Cameron has suggested a football team to represent Britain at the 2012 London Olympics could be decided by a home nations tournament.
Mr Cameron said a play-off could decide which of the UK's four national teams represented Britain at the Games.
The football governing bodies of Scotland, Wales and Northern Ireland are all opposed to the notion of a combined Great Britain team.
They fear the implications for their own futures as separate entities.
Britain has not had a football team at the Olympics since 1960 because of concerns a combined British team could affect the status of individual nations within football's governing body Fifa.
Mr Cameron told BBC Scotland's Politics Show there was a need for one national team when it came to the Olympics.
"Maybe the answer is to have a home tournament, see who wins and that team goes forward, but for the Olympics we've got to settle this so there is a representative team," he said.
Prime Minister Gordon Brown has expressed his determination to reach a deal over entering men's and women's British football teams at the London games.
The Scotland, Wales and Northern Ireland football bodies have opposed any such move in case it affects their international status.
Scottish First Minister Alex Salmond said: "What we're talking about in the Olympics is an under-21 team and the idea that, in any sense, we should risk the future of Scottish international football for the sake of participation in an under-21 tournament in the Olympics, I think it simply daft."
The first minister urged all parties to stick with the Scottish Football Association's position.
He added: "They take some knocks from time to time, but they know infinitely more about the workings of Fifa than David Cameron, Gordon Brown, or even Alex Salmond."