Just in case this has a bearing on whether it is likely to be a Jasmine (I don't know anything about them) but I should have mentioned that this shrub is basically a thick upright woody main stem, approx diameter of 1-1.5 inches I'd say, and all the leaves are at the top of the stem, I'm assuming that is because it has been competing for light.
I shall read up on Jasmine tonight, together with all the other suggestions for the others. Really glad I posted as it's helping me a lot.
SP x