In a word, don’t. Just don’t.
Yesterday, a reader of my blog sent me a letter. She works for a SME in the UK, and the CEO has written to all employees in order to ‘help them understand’ the key issues around the forthcoming European referendum.
Only, it wasn’t so much a helpful guide as a list of reasons why he thought they should vote ‘leave’. His method of ‘help’ was to regurgitate much of the leave campaign rhetoric. Including some of the slightly dubious stuff. Essentially it was his opinion; what he thinks might be best for his business and sent to all his employees.
Here’s the thing. If someone wants to better understand the issues before deciding how to vote then there are plenty of ways that they can go about it. Watch a debate, read widely – from both sides of the argument. But voting the way your boss thinks you should is no way to make a decision. You might as well just read The Sun and be done with it.
As employers we have many responsibilities. Attempting to influence people in how to vote isn’t one of them.
People Stuff 
I was involved in a debate on LinkedIn about this yesterday and there is a fine line between informing employees of possible business consequences (which I think is entirely legitimate) and trying to influence how people vote (which isn’t in my view). For example – if a company said to its staff “55% of our products are exported to other EU countries. We have concerns that these markets might be restricted if the UK leaves and our view as a company is that the UK should remain in the EU”, is that
a) trying to influence them into voting remain because they are worried about their job or
b) making them aware that a particular vote might affect their employer – which might then have a knock-on consequence for them as individuals.
It’s not like a General Election where the issue is “which party can manage the economy better for the next 5 years?” – it’s a fundamental choice that will affect every person and organisation in the UK, for good or ill, and people should make their choice on the fullest possible information. However, where providing information crosses into persuasion is a difficult point.