Hello I am a solicitor with 20 years experience. I will try to help you with this.
Can you tell me a bit more please? How long as the porch been there? Why do you think the neighbour/HA want it removed?
The basic position is that as long as your porch is their legally then the HA/neighbour can do nothing about your porch. If they want to remove theirs then generally they will have to make sure that in doing so they do not damage yours.
the porch has been there since 1998 and as I am told the neighbour or the housing ass dont want the up keep of the porch as there side not mine needs work done on it
They can not demolish the thing if it will damage your side. I think they will either have to maintain it or reach agreement with you about removing it in a way that is acceptable to you eg by re-instating a new porch for you + some compensation for inconvenience.