I was a little taken aback by it's size and it looked very distincitve to me, not like anything I have seen before in the UK.
The picture doesn't do it justice (I only had an old mobile phone to photo it with), especially the colours, I would describe it as grey with a darker grey-brown pattern on it's abdomen which was noticably large and almond shaped. It's legs looked thick and muscular. Body length (legs excluded) it is hard to feel accurate, but at a guess 1.5-2.5cm, it was the most intidmating looking spider I've seen in the UK.
I've looked on a couple of UK spider ID sites and have found nothing that really looks like it.
Does anyone know what it is?