Fás has been told by the Labour Court it is acting in breach of agreed industrial relations procedures in only promoting staff who are prepared to decentralise to Birr, Co Offaly.
The court's recommendation, published on its website yesterday, could have significant implications for the Government's decentralisation programme.
The court upheld a claim by Siptu that the promotions policy pursued by Fás, the State training and employment authority, was a breach of agreed procedures.
But it recommended that the two sides refer the matter to the Government's decentralisation implementation committee for further discussions.
In the meantime, Fás says it plans to continue with its policy of limiting head office promotions to staff who are prepared to relocate to Birr. The policy was described yesterday by Siptu Fás branch organiser Greg Ennis as "promotional blackmail".
New recruits to the agency's headquarters in Dublin must also commit to relocating to the midlands town when Fás moves there as part of the Government's decentralisation programme.
The move is scheduled to take place in 2009, but only seven of the organisation's 400-odd head office staff have expressed an interest in relocating.
However, just over 50 Fás staff are now committed to the move as a result of its policy on promotions and new recruits.
Just over half are people who have been promoted since the policy requiring them to sign up to decentralisation was put in place. The remainder are new employees.
Siptu, which is refusing to co-operate with decentralisation, told the court that the Government's programme was supposed to be a voluntary process.
Many staff had not applied for promotion because of the Fás policy, the union added, and their careers were being adversely affected as a result.
The court said it was "of the opinion that Fás is in breach of the consultation procedure" provided for in its industrial relations agreement with Siptu.