I'm getting unwanted advances from a colleague. What can I do about it?

Working closely alongside each other day in day out, means people often develop strong feelings for co-workers, but this can cause problems when the feelings aren't mutual. If your office admirer won't take no for an answer, it can make things very difficult for you, affecting your well-being as well as your work.

You might want to begin by trying to explain to your colleague how the behaviour makes you feel. He or she may not have realised how upset you are. You could do this in writing if you don’t feel able to do it face to face. You could rehearse the conversation with a union rep or your colleague, and take someone with you if it makes you feel more secure.

If you have tried an informal approach, or if you don’t want to do this, you should raise the issue with your line manager. Again your union rep can help if you have one. Your employer must take any suggestion of sexual harassment very seriously.

If your line manager is the person making the advances, you could approach another manager, or HR.

It is a good idea to start keeping a diary at this stage (which you should keep at home), recording incidents that have upset you, what the colleague did, how you responded, the steps you took to try to get the problem to stop (e.g. emailing your manager or HR), and what happened.

You should also keep any evidence – for example, copies of texts or emails, gifts or screenshots of unwelcome social media postings.

Ask your manager to follow the company policy for tackling harassment. If the problem cannot be resolved, you will need to consider putting in a formal grievance and, if necessary, taking employment tribunal proceedings. The legal definition of sexual harassment involves showing that you have been subjected to unwanted sexual conduct that violates your dignity or creates an intimidating, hostile, offensive or humiliating environment for you.

People may often attempt to pass off cases of sexual harassment as 'a bit of fun' – especially at times like Valentine's Day or at office parties – but they're no fun for the person being harassed, and you shouldn't be expected to just laugh it off. Behaviour of this sort is unacceptable, as well as unprofessional, particularly if you have made it clear you don't like it.

Even if your harasser thinks their behaviour is not offensive, they will be guilty of harassment if they persist with the behaviour once it has been made clear to them that you want it to stop.

Note: This content is provided as general background information and should not be taken as legal advice or financial advice for your particular situation. Make sure to get individual advice on your case from your union, a source on our free help page or an independent financial advisor before taking any action.