When braking to a stop and dipping clutch, car revs to nearly 1500 until I release brake pedal.

Any ideas?

Sounds silly.

Have you got fat shoes n pressin both? Haha

Err nope.

Still not been able to solve this even after a full service and replacement of all filters

My wifes Citroen had a similar problem and it took me a few days to figure it out.  The accelerator pedal was catching on the ribbing of the rubber mat underneath causing it to stick on slightly.  I pulled the mat further back and it sorted the problem.