Car jumps once driven for a little while!?

I Drive a Nissan Micra 1.0 L Reg, if the car has been sitting there all night and not been used i can drive it for a little while (half a day at low speeds short jounreys) but once like the engine - car gets warmed up i cant drive it at high or low speeds with out it jumping (like someone was appying the brakes on and off quickey) Please Help