No spanish speaking at work place

management has try to mention that spanish should not be spoken at the place of work at any time (County workers). Spanish speaking workers not necessary of latin background should not speak spanish among themselves.
what are my rights? Is this legal? Some of these workers are spanish speaking title do to the cliantel we have. Comments like english english you are in america are mentioned as a joke but yet not really joking. They explain how do I know you are not talking about me?

This is definetly illegal as an employer cannot force employees to speak english only during there free time, breaks etc.... If the position requires you to speak english only than its withing the law, but this doesn't sound like it.

Have you gone and spoken with your Human Resource Department? If not I suggest you do. If after speaking to them, if nothing is done to rectify the problem then you need to file a complaint with EEOC or your state human rights division.