Renault Espace sounds like riding clutch when not even using it?

On way home from Nottingham and car was warm and was tootling along at 60-70 mph and intermittantly the car kept making noises like I had ridden the clutch when not using the clutch at all. It was progressively getting worse so have only used it as needed locally but not as bad as it was. But also when we were using clutch control on hill it left a terrible burning smell. My dad dipped the clutch etc to see if car stalled but seemed to be no problem. At a loss. Don't know whether needs adjusting etc etc or new? Is it safe to drive?