Thank you very much for your help. I will give repotting a go and see if that helps. I am worried it might be too far gone but probably worth a try. I think you are right that the area is diseased, it certainly doesn't look healthy. I would be willing to plant it out if you think that may help? Is it worth trying to clean the diseased area up or is this likely to be futile?
On a bit of a side note. I have couple of blueberry plants growing quite close to eachother. One has done well and produced fruit while the other one has very red leaves. I have added a bed of grass clippings as a mulch to see if that helps incase it is nutrient deficient. Do you think this will help or is there something else I could do?
Thank you, this is an incredibly helpful forum!
Pete