Dear sir,
It will depend how treatment to such employees in Supervisory cadre and rest of workmen together or without unionized staff is being given. If your organization has a system of wages payment bargain-able as a matter of precedence and they are also directly or indirectly bargaining or made to take advantage following workers wages increase , then definitely yes they can plot this type of activities in concert with workmen. Merely, calling Supervisor by designation, wages limit etc, are secondary thing of no consideration.
Employee relations is not exactly advancing over regulatory process. Today, staff unions are there , bargain salaries , settling employees demands and all disputes in big corporate offices. What is happening in Banks? Forget the Bank, IAS, IPS have their associations? and it is a joint strategy inside at full power attempted by every employee other than owners to have maximum increase in payments. HR must recognize scenes behind and out of curtain to play the desired role as game changer.
Regds,
RDS Yadav