Mayfield05
Realistically there are three avenues open to your husband:
1: Seek to make a formal grievance within the process using the Company's own grievance procedure. If there is no such procedure, or the procedure is not being adequately followed, he could refer the matter to a Rights Commissioner / Labour Court under section 20 of the Industrial Relations Acts as a "trade dispute". The benefit of this approach is that it is very cost-effective
However, this process is only of real use if the company is unionised, or a trade union is sniffing around for recognition. The reason for this is that any recommendation made by a rights Commissioner / Labour Court is not binding on the employer. It can only really be implemented on foot of a threat of industrial action.
2: Resign for his employment citing "constructive dismissal" - i.e. the actions of the company left him with no option but to leave. The appropriate forum in this regard is the Employment Appeals Tribunal under the Unfair Dismissals Acts. From the limited evidence presented, there does appear to be a possible basis for such a claim.
The Unfair Dismissals route is relatively cost-effective in that you do not need a lawyer. However, I would suggest that it might be a little foolhardy to go without. Then again, I am a lawyer so I may be biased!
The major downside to this approach is that, obviously, there is no guarantee of success and it involves your husband terminating his employment. There may be a period of unemployment to consider. If yo uare successful, your husband will not get his job back as it is clearly a case of trust and confidence having broken down . As such ,your husband will receive compensation for any financial loss incurred by leaving his job. This does not include any compensation for distress, bad treatment etc.
3: The third approach is the most risky - albeit with the highest possible reward. Your husband could bring a civil action before the courts, based on breach of contract and possibly stress. If it is the case that your husband is being side-lined, he could seek an injunction to restrain his removal for his current post - pending resolution of his action regarding breach of contract.
The obvious downside to this approach is cost. The costs of bringing such an action are astronomical. However, so too are the costs of defending such an action. This may bring about a settlement scenario where his employers do not wish to run a case they may possibly lose (with the cost consequences that may result in terms of paying your costs). The potential settlement amount may be very significant.
Thus, this creates a high risk/reward ratio. I would suggest that you secure adequate and detailed legal advice and then think long and hard about your next step as a family.