Whoa, You could tell I was in a rush when I wrote that OP.
My garage is not next to the house, I live in a semi detached house, my neighbour to my right has his garage with mine attached to the other side.
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He's allowed me to use his power supply if I pay for it. I know if he moves or I move I will have to stop what Im doing.
O'rly

I have contacted an electrician and he said the legalities of putting conduit over some ones property is a 'grey area' and he was not prepared to do the job. Please be constructive in the future. Thank you.
If anyones got any advice on how to get a Light in my garage please do tell.