It's a Rhododendron, one of the larger leaved hybrids. It's not looking too happy I must say as it should be more branched and fuller looking. The leaves also look very yellow. It could be because of a combination of things. Dry at the roots and soil that is not acidic enough. I see you are in Essex and I don't think the soils in the east are particularly acidic. Mulch heavily around the base with ericaceous compost and give it a good feed with an ericaceous liquid feed. It may become better over time.

evening Fractal, thank you for your quick reply,I have a bag of ericaceouss,now it's finished flowering should i move it,replanting it with the new soil,and to my back garden where it's more damp??Or what do you suggest,thank you

Evening :-) I wouldn't move it now though this coming autumn would certainly be an option. Lift with as good a rootball as possible as with any plant. Keep it well watered (good soak once a week) for now during dry weather and perhaps mulch with that compost too. I would also give it a liquid feed. If you are careful, when it has finished flowering, remove the seed pods too so that it doesn't waste precious energy forming seed.

Prepare the new planting position just before the move with plenty of ericaceous soil worked into the spot its going into and after planting, mulch heavily around with more compost. Good luck with it.

A big thank you,yes i will follow your advice, and wait till autum.

If at all possible make sure it isn't in full sun - these are woodland shrubs and need dappled shade.

that makes sense moon grower,i have that in my back garden on one side so i know just the right spot for it in the autum

Great! Makes sure to plant in acidic/ericaceous soil.

yes i've got it ready lol, thank for all your help your great