For any family that has lived through a divorce and has settled into new routines with parents living apart, the inevitable will happen; a new partner will appear on the scene. In an extract from her book, Help Your Children Cope with Divorce, Relate psychotherapist Paula Hall talks about helping your children adjust

Sooner or later, either you or your partner is likely to meet someone else. The timing of this new union is extremely important. Ideally, you shouldn't consider introducing anyone new into your life until both you and your children have adjusted to the separation and idea of having both parents in separate homes. Your children need time to accept that your relationship with the other parent is over and there's no chance of reconciliation. If a partner is introduced too early, children are more likely to feel they are a replacement.

Suzie Hayman, author of The Relate Guide to Second Families and counsellor on the BBC's Stepfamilies series says: 'Of course, real life doesn't always go to plan, and you may find yourself falling head over heels in love and wanting to combine lives with a new person as soon as possible. However reasonable or desirable this feels, thinking of your children's reactions and needs may help you take it at a slower and more measured, planned pace.'

However, the ending of your relationship may have been triggered by meeting someone else. In the majority of situations when this happens there were already problems in the relationship, and someone new is the catalyst for bringing it to an end. But from your children's perspective, and possibly from your ex's as well, this new person may be seen as the cause of the break-up. In order for your new partner to be accepted as part of your future family, you should try to ensure that you have time living separately while your children adjust.

Understanding children's reactions

Most children want their parents to be happy. And most realise that, in part, means meeting someone new. However, while they may want you and your ex to meet someone else, they may also struggle with the impact that will have on their relationship with you. Many parents become particularly close to their children after a relationship breakdown, so it's especially hard for them to see you getting close to someone else.

Feelings of jealousy are natural, and your children will need your help to understand that you will not love them any less because of it.

A new partner also signals the end of any reconciliation fantasies that your children may have had. It's common for children to cling to the hope that one day Mum and Dad will get back together. The introduction of a new partner means the end of those dreams.

Some children can feel afraid that a new partner will get in the way of their relationship with the other parent. They may become angry and resentful, and spend a lot of time making comparisons between the two. If they particularly like the new partner, they may struggle with feelings of disloyalty and go to great lengths to act as if they don't like them, which can be very confusing for everyone.

When just one parent has a new partner, children can become anxious for the other, single parent. They may become more acutely aware that the other parent is alone, and want to spend more time with them to prevent them from feeling lonely.

Suzie Hayman adds: 'Children living with separation or divorce often take on the role of carers, or parents, to their parents. They worry about them, care for them and even feel responsible for them. They may see themselves as the missing parent's representative and that it's their job to act as, or in the interests of, the other parent. They can see an incoming adult as a rival, challenging their position, and so feel it's their place to resist invasion or takeover.'

The first introduction

Start by casually mentioning in conversation that you've met someone. Make them aware when you're going out to meet them, and let their natural curiosity begin to build.

Over a relatively short period of time, depending on the age of your children, they'll probably begin to ask questions: What's he/she like? Where do they live? Do they have children? How old are they? Are you going to get married? Yes, your children are likely to get to the nitty-gritty much earlier than you think. The deeper question underpinning all these is: How much impact is this person going to have on my life?

Be as honest as you can and reassure them that you're not going to make any changes in their life without giving them plenty of warning.

Once they've begun to ask questions, ask if they'd like to meet them. If they say no, be aware that this may be out of loyalty to your ex. Within reason, give them as much time as they require. But if you feel they could procrastinate for ever, then you may need gently to push things forward.

Planning that first meeting

Whenever the introduction happens, make sure it's low key. A first meeting will often work best around an activity where there's an additional focus, for example, tenpin bowling or a trip to the park. Subsequent meetings should build gradually on this and be taken at your children's pace. You do need to spend time with a new partner in normal, everyday contact, as well as fun trips. Otherwise, children start expecting that it will always be fun and games, and find reality a shock.

If you're the resident parent and you're still living in the family home, then you must be aware of how it will feel for the children when your new partner visits the house. If possible, let the children get to know your new partner away from home at first, and when they first visit, make it brief. As the length of their visits to your home increases, try to avoid slipping into any familiar routines, such as your new partner sitting in your ex's chair. This will help to re-emphasise the fact that your new partner is in no way replacing the other parent.

Relate: Help Your Children Cope with Your Divorce by Paula Hall is published by Vermilion (£8.99).