The chief executive of the FAI, Mr Fran Rooney, is facing a fresh challenge to his plans for reforming the sporting body following the declaration of strike action by some clerical staff.
Some 25 employees affiliated to SIPTU said they would begin strike action on Monday over the FAI's "reneging" on the introduction of a pension scheme.
SIPTU official Mr John White said it believed it had concluded negotiations on the implementation of the scheme, based on a trust deed. However, FAI management had since informed him the deed was "not acceptable, leaving us back at square one".
Mr Rooney said talks had only been "close to finalisation".
Talks over the pension scheme have been ongoing for more than 18 months, with tensions rising in recent weeks over the union's refusal to negotiate with a human resources consultant brought into the FAI.
The strike begins just six days before the Republic of Ireland's crucial European qualifier match against Switzerland in Basle. A spokesman for the FAI said the action would not disrupt preparations for the game as a "contingency plan" was in place.
