Contentious plans to allow footballers born north of the border to play for the Republic have been raised in Westminster by outraged MPs.
Jeffrey Donaldson has launched a Parliamentary campaign to stop the changes being introduced, claiming it would "seriously undermine" the development of football in the province.
It follows FIFA's announcement last week that it wants players to be able to choose to represent Northern Ireland or the Republic of Ireland at international level.
The DUP MP for Lagan Valley fears it would drain Ulster of its best footballers.
He said: "We are very concerned about the suggestion made by FIFA. It would set a dangerous precedent in international football and cause problems for small countries who rely on home grown players."
He added: "It would seriously undermine football in Northern Ireland and we give our full support to the Northern Ireland football team, the Irish Football Association and the supporters clubs who are all opposed to these plans.
"We believe those born in Northern Ireland should play for Northern Ireland."
FIFA are looking at changing the rules after Manchester United midfielder Darron Gibson, who was born in Northern Ireland and played for the province as a schoolboy, represented the Republic in a Euro 2008 qualifier.
The Football Association of Ireland believes it can choose players from the north because anyone born on the island can hold an Irish passport under the terms of the 1998 Good Friday agreement.
FIFA's executive committee will make its final ruling after hearing evidence from both associations.
Mr Donaldson tabled an Early Day Motion in the Commons, which has been backed by Tory Christopher Fraser and Labour MP Kate Hoey - along with the DUP's David Simpson, William McCrea and Gregory Campbell.