The Irish Protected Disclosures Act, under section 23, prohibits an employer from forcing an employee to sign a gagging clause. It's very clear, irrespective of what. There are either exceptions for those sharing information that might be related or have an impact on national security. However, where public contracting is believed to be subject to wrongdoing, there are no provisions to prevent an employee from sharing information or making protected disclosure about that.
On March 21st, 2017. See this statement in context.