Outside of the medical profession, the state services sector has clauses around political neutrality in its work contracts, but there is still plenty of scope for expression of political opinion.
"There are clear allowances for political activity within the contracts," Haggard says. "But in public-facing roles it's probably considered inappropriate for strong political views to be voiced."
There are additional restrictions on the way upper management express opinions, and political neutrality is expected.
The Employment Relations Act has no explicit provisions on the expression of strong opinions in the workplace, but freedom of expression is protected in the New Zealand Bill of Rights (1990) and the Human Rights Act (1993), which cover all aspects of New Zealand society, including the workforce.
Section 14 of the New Zealand Bill of Rights states: "Everyone has the right to freedom of expression, including the freedom to seek, receive, and impart information and opinions of any kind in any form."
Even so, Haggard says issues can arise if beliefs encroach on the way an employee performs their duties; but this can be hard to prove.
"If an employer was concerned about the way in which an employee's political expression was affecting their work performance, there would have to be pretty robust evidence to back it up," says Haggard.
Carl Blake is a senior associate at Simpson Grierson, specialising in employment law. He agrees there are grounds in which an employer could take action against an employee if they voice their beliefs in an inappropriate manner.
"There are two factors here; first, are the actions of the employee undermining the confidence of the employers? And second, do such actions bring the company into disrepute?"
Blake gives the example of someone attending a protest march wearing a recognisable work uniform.
"If someone is legally protesting by walking up Queen St in a demonstration, this shouldn't be enough for an employer to bring action against them. But if they become engaged in more extreme behaviour, this could be seen as bringing the company into disrepute, and they could have grounds for action."
When it comes to behaviour within the workplace, issues can become slightly muddied. Although the right to freedom of beliefs is enmeshed in law, if people aggressively push their beliefs on others in the workplace this could be seen as disruptive work practice.
"You need to look at what is considered 'reasonable' in the workplace," Blake says. "If the behaviour can be seen as outside of what is generally considered reasonable, issues could arise."
If voicing opinions is disturbing others or interrupting the workplace it could easily be argued that the person involved is being disruptive, that their behaviour is having an adverse affect on productivity.
"It's not what the employee believes, but their behaviour that's the problem. And this should be highlighted when it comes to disciplinary procedures."
Some companies adhere to a strict dress code, and wearing religious jewellery or culturally distinctive attire may not be acceptable.
"If it's a subtle demonstration of belief it should be fine, but again you need to look at what is considered 'reasonable'. Action could open a whole can of worms."