I had a brief fling with this man for about 6 months. He is married and I knew it wasn't going anywhere nor did I want it to.

It all fizzled out and I started to ignore his calls. He sent two lots of flowers to my home with cards asking if he had done something wrong. I decided to just keep ignoring him then one day I came home from work and he was at my door.

Gosh, it's a stalker moment.

I explained that our fling was over and he should concentrate on his wife or find another girl to see.  He asked to come into my home but I refused and told him to leave. He did go but he is still ringing and sending stuff like jewellery and underwear. I left a brief message on his phone again saying that I was no longer interested in seeing him and to stop sending presents because he was wasting his time. I was very straight to the point without being unpleasant and he went quiet for about 2 weeks. I came home from work again one day and he was there again. I told him he was harrassing me and I felt uncomfortable. He said he would leave his wife and move in with me. I laughed and said that would never happen and I just went in the door and shut it behind me. He shouted through my letterbox for me to wait and see. Thankfully he left. He has since sent me a heartfelt letter saying he wants to marry me etc etc and he can't forget me. He said that if I say the word he will bring his stuff right over and move in.

For him to actually have an affair, it says he doesn't think much of his wife in the first place.  But to actually proclaim he wants to marry one of his affairs and to persist in stalking her when she says no, shows too things.  He's desperate to get away from his wife and also really does fancy you a lot. You've got him hooked!

He has now started leaving messages on my phone saying how much he cares. I am at the point where I am not sleeping well and unable to concentrate at work, I feel like he's watching me or he might be there when I get home. I have decided to move when I come to the end of my lease in October just to try and get rid of him. I have also bought a new phone but I don't know what else to do.

That is pretty drastic action, but I don't think you have any other option really but to move houses.  He probably thinks, if he's persistent then you'll crack and take him back anyway.  But really mentally this guy has now got an unhealthy interest in someone who doesn't feel the same and he needs to get over you. It's perhaps the length of time you had the affair that makes him want you so much.  6 months is quite a long time and enough time to get very attached to the other person.

I mentioned it to my father who was very unhelpful (leaving the bit out that he was married obviously!)and just went on about me being too independent for my own good. I rang the police and they were rubbish.  They say he hasn't actually committed a crime and to just carry on ignoring him.

I'm surprised they couldn't give you some advice at the very least, because they should see alarm bells of things could get dangerous with this guy. But to a certain extent they really can not do anything unless he's committed a crime.

However, 4 months is along time to put up with this til I can move. Have you any reasons why he keeps on contacting me?

Yes, 6 months is a long time to have an affair, he's obviously grown attached to you and hasn't got much of a decent relationship with his wife.  He sees you as a once in a lifetime opportunity to get away from his life, the perfect match for him and he's hooked on you. Therefore he's trying to do everything that a guy could think of doing to win you back, like showering you with gifts and telling you how much he cares for you.  The best way to convince you is to meet you and talk to you about things and that's what he's trying to do.

Also how can I convince him it's over?

There are a few possibilities that spring to mind.  He wants to be able to talk to you.  Maybe you could arrange to meet up in a coffee shop or other public place.  Take two of your friends with you and get them to sit at another table as protection.  Then discuss with him his issues, then give him your honest answer to everything he says.  As in I'm not interested anymore.  The only other things I can think about is to dish everything that is bad about you to him, even tell him that you have a Sexually Transmitted Disease or long term illness which is deadly or would require a lot of care.  Or even threaten to send the presents he sent you to his wife.  But the best way might even be to just ignore him and as you say move house.

Please help me as I feel I have lost control of the situation.

Maybe there's some web sites on the internet that give advice on helping to get rid of stalkers. It's not really an issue that I'm strong on.