freelander revs fault

I own a 98 freelander 1.8, when i am in a traffic jam moving forward stop starting the engine revs start increasing with my foot off the gas. The only way to stop it red lining is to depress the accelerator and release it, this only works until i pull off and when i stop again up go the revs again!
Please help as this is very embarrassing driving down the high st.
ps. only happens when the engine is hot!

not sure but it sounds like the stepper motor might be going wrong.

Try Idle Control Valve Had This Problem On A Granada