Loose front brake caliper

damocles10

I have a set of Campagnolo Chorus 2006 brakes and I have recently noticed the front brake caliper has become loose. It moves freely from side to side and rubs the rim on the left hand side when the brakes are applied. They don't move back and forth and the bolt behind the brakes in the fork is tight.

What do I need to do to tighten up the brake so it remains in it's neutral position?

Any advice would be welcome.

Cheers