The Acas guide Race discrimination: key points for the workplace warns employers to be wary of prohibiting or limiting the use of other languages in the workplace as it could potentially be discriminatory:
“Managing languages at work
The increased movement of people around the world means it can be quite common for organisations to employ staff from many different countries or ethnic backgrounds. As a result, there may be employees for whom English is not their first language. Often, there may be a number of employees who originate from the same country or share a common language which is not English.
However, an employer:
can specify a language of operation, usually English, for business reasons. However, in Wales some jobs require the holder to speak both English and Welsh
can insist on recruiting a job candidate who has skills in English necessary for the job, but it must not select based on assumptions about race, nationality, or ethnic or national origins. Again, in Wales some jobs require the holder to have skills in both English and Welsh necessary for the job
should be wary of prohibiting or limiting the use of other languages within the workplace unless they can justify this with a genuine business reason.”
A race discrimination claim succeeded in the case of Jurga v Lavendale Montessori Ltd, in part, because Polish-speaking employees were reprimanded for speaking Polish to each other in their breaks while Italian colleagues were able to speak Italian during breaks without objection.
Equally, in the 2012 case of Dziedziak v Future Electronics Ltd, the Employment Appeal Tribunal (EAT) found that an instruction given by a manager to an employee not to speak in her own language (Polish) at work was direct race discrimination on the grounds of her nationality.