Requiring All Staff to Speak English

We would like to introduce a policy requiring all staff to speak English during work, but are worried that we could be accused of discrimination. How do I handle it?

Amanda Magee of Tughans writes:

When introducing a policy requiring employees to speak only English in the workplace, there is always a risk that the policy will be seen to be indirectly discriminating against those employees for whom English is not a first language. Whether or not such a policy is indirectly discriminatory, will depend on whether or not you have legitimate business needs for employees to speak in English while at work, which are sufficient to outweigh the discriminatory impact of such a policy on the