If you can, the first thing to do is to speak to the person directly, and ask them to stop. There are all sorts of situations in which this might not be possible or safe, and you’ll be the best judge of that. But sometimes, if you can talk to a person – hear their perspective, set their facts straight, and explain the impact they are having on you – it will be enough to turn the tide.
If the person is a colleague, and they are persistently undermining you, think about how you want to respond. If you think it needs to be addressed formally, you can raise a complaint through the Code of Conduct process, but I would suggest approaching that with a lot of care. It is not a very effective process, and it can’t guarantee that the person will change their behaviour. Using a formal process can make the person who opposes you look like a martyr, and make you look like you’re in the wrong. It’s a horrible upside-down form of justice, but it’s too often the reality, so I think it’s wisest to be honest about that.
There are other approaches you can use, if the person mistreating you is a fellow politician. If it happens during States Meetings, call them out on it in public or ask a supportive colleague to do so on your behalf. It it’s happening behind the scenes, one way to balance it out might be to consciously build relationships with other States Members. There’s nothing wrong with saying: “I think we’ve gotten off on the wrong foot, can we have a chat and try to understand each other better?” or “I think you’ve heard X about me, and it’s not the whole story, can I give you my perspective?”. There are some people whose minds you’ll never change, and I think you’ll have a fair idea of who those people are, but there is no harm in trying to build mutually respectful working relationships with your colleagues – even people who are on vastly different parts of the political spectrum to you – and you may find that it helps to balance out some of the malice from those who really don’t like you.
If the person is not a politician, your options are probably more limited. Start by thinking about the harm that is being done by this person’s vendetta. If they are making you feel threatened or unsafe, then ask for the help you need to make sure you and your loved ones are protected. If they are undermining your reputation in public, then consider whether you want to make a public statement or give media interviews to refute what they are saying. (This isn’t guaranteed to be a smooth, or even a fair, process. The media may interrogate you. People may still hear what they want to hear even after you’ve given your side of the story as fully and honestly as you can. But if you are being attacked in public, you may feel an equally public response is needed to help set the record straight.) If they are undermining your reputation with your colleagues, then the same strategy of trying to build bridges one-by-one and ask people to hear your side of the story, may help to provide you with a buffer of support.
I should say – one situation you might come up against is a constituent, or a person who uses the services provided by a Committee you sit on, who is not happy with the outcome of a meeting you’ve had, or a decision about a service they receive. It is their right to air their grievance in public, even to go to the media about it. In doing so, they may completely misrepresent what has happened. Tempting though it is to set the facts straight, you have a duty to protect their confidentiality, which means you can’t necessarily answer back. Frustrating as it is, sometimes you just have to bite your tongue and live with that.