I think i have penduline tits visiting and have just discovered a hanging nest in a tree near some roof works. Will the birds use the nest again? Do I protect it, remove it to preserve it as i fear it will be damaged.

If you are in the British Isles it is highly unlikely to be Penduline tit, they are only very rare and occasional visitors to the UK. If you can put up a photo of the nest it will help to id if it is Penduline as its very distinctive. I don't think they reuse old nests but I think they may recycle the material.
If you are in the UK it could be something like a Long-tailed tit

CinJ