auburntsts is right, only time and low temperature can clear this beer. That's a little more than just chill haze. What kind of yeast did you use? Wyeast 1968 London ESB yeast is a high flocculation yeast which should settle right out in the primary. A slow flocculating yeast will remain in suspension for a bit longer but will eventually settle out if you cold crash it as close to freezing, 32F, as possible. If you want to use fining, unflavored gelatin is cheap and easy. Unfortunately in your case, the beer is already carb'd and fining may not be effective, in fact it will foam all over. Next time, throw in a whirlfloc or 5g Irish Moss into the last 15 minutes of the boil. If you need to clear it further, chill the serving keg very cold. Mix 1 tsp unflavored gelatin into 1 cup of 120-140F water (distilled). Stir until dissolved and pour it into the keg, no need to stir it in. Reseal, purge O2, and set to carb pressure. Wait at least 2 or 3 days to clear, longer if your beer needs to carb up. If there is chill haze in the beer (because the keg has been chilled), the gelatin should take care of it and force it to the bottom. When the gelatin settles out at the bottom of the keg, it sits in a cloudy haze and slightly gelatinous. Before you move the keg, reduce keg to serving pressure and pour off a couple of pints or until it starts running clear. I have found that the gelatin cloud at the bottom of the keg is very sensitive and if you try and pick up the keg and move it, the cloud will stir up and mix with the beer near the bottom and when you start pulling pints, it will take quite a few until everything settles down again. In the meantime, if this beer tastes good, enjoy it in an opaque glass or cup, there is no rule that says beer must be crystal clear.