Another option is just to plug it into the regular receptacle via wall wart and pocketsocket and then use what in the US is called “raceway” — I don’t know the term in the UK. But it’s just a hard plastic cable cover that you put over the cord as it runs up the wall. These are usually paintable and can look quite elegant. See the following topic for discussion and pictures:
It looks like in the UK these covers are called “cable trunking” or just “cable covers.”
