A manager threatens disciplinary action against an employee for comparing pay with colleagues.
The argument treats an internal 'company policy' as if it can override a legal right. A workplace rule or contract term cannot lawfully take away a statutory right. Calling the conduct a 'serious breach' does not make it one — the label borrows the appearance of legal authority without any legal foundation. The premise collapses the moment you ask which law makes discussing your own pay unlawful, because none does.
After you respond, they may push back with these arguments. Members get the full rebuttal for each.