Thanks very much sirp2000, I went straight on and bought a ticket, left work jumped on a train and had a great evening. Not only great price, face value but a really good seat on the floor in the middle just in front of the sound desk.

I know it's unlikely but just in case anybody has a single ticket for tonight they can't get rid of and it would be available to be picked up somewhere in London around 5 leave me some contact details. I am happy to pay face value plus a bit to cover your costs. It's 12:30 and I have about two hours...