Ford Mondeo V6 ST24 W reg. Revving on its own when clutch down when braking and changing gear.?

When you turn the engine on its fine, after a few miles when its warm and you brake for a junction the revs start going up steadily on their own. Plus when you change gear, up/down its starts again no matter what speed or gear you are in. Basically when ever you de-press the clutch i starts revving up to about 3000rpm.